University of California, Los Angeles, 1985
Annual Canadian Conference on Operator Theory/ Operator Algebras,
July 1986
University of California, SanDiego, 1989
University of Georgia, Athens, 1989
Mittag - Leffler Institute, Stockholm, 1991
Summer school on Multi-variate Operator Theory, Seattle, 1993,
Texas A&M University, College Station, 1993
International Conferenece in honor of B. Sz.-Nagy, Szeged, 1993
B. Sz.-Nagy Memorial Conference, Szeged, 1999
SUMRIFAS, Texas A&M University, College Station, 1999
Graduate Centre, CUNY, New York, 1999
University of Joseph Fourier, Grenoble, May 2001
University of Pierre and Marie Curie, Paris, June 2002
CIRM, Luminy, June 2003
Texas A&M University, November 2003
Ben Gurien University, June 2005
Romanian Institute of Mathematics and West University in Timisoara,
Plenary talk, July 2006
Ben Gurien University, July 2007
Texas A & M University, Oct 2007
Operator theory with Application to Geometry and Topology:
In Honor of Ronald Douglas' Seventieth Birth-day, June 2-6, 2008, China
First Indo-Brazilian Symposium on Mathematics, IMPA, July 28 - August 1, 2008
A sheaf theoretic model for analytic Hilbert modules 
,
Hilbert Modules and Complex Geometry, Institute for Mathematics, Oberwolfach, April 5-9, 2009
Chalmers University, Oct 2010
A sheaf model for semi-Fredholm Hilbert modules I, Analysis Seminar, The University of Newcastle upon Tyne, October 28, 2010.
A sheaf model for semi-Fredholm Hilbert modules II, Analysis Seminar, The University of Newcastle upon Tyne, November 4, 2010.
Yorkshire Functional Analysis Group seminar
Unnivesity of Leeds, October, 2010
Reproducing kernel for a class of
weighted Bergman spaces on the
symmetrized polydisc, AMS Sectional Meeting Cornell University, September 10-11, 2011
Quantum Probability, Noncommutative Geometry, Quantum Information
ICMS, Edinburgh, 16th - 18th January 2012
Pure Mathematics Seminars, Lancaster University, January 2012
The complex analysis seminar, University of Vienna, April 2012
Chalmers University, Jun 2012
Complex Geometry and Operator Theory at IWOTA
University of New South Wales, July 16-20, 2012
Classification of homogeneous operators in the Cowen-Douglas class, Indo-Spanish Conference on Geometry and Analysis, ICMAT, 10-14 September 2012 and University of Marburg, June 12, 2012.
Flag structure
for operators in the Cowen-Douglas class, Functional Analysis Seminar, University of Saarbrucken, February 12, 2014.
Flag structure for operators in the Cowen-Douglas class , Hilbert modules and Complex geometry, Institute for Mathematics, Oberwolfach, April 20-26, 2014.
Contractive and completely contractive homomorphisms over function algebras, Functional Analysis Seminar, University of Leipzig, July. 21, 2015.
Homogeneous Hermitian holomorphic vector bundles and the Cowen-Douglas class, Hilbert Modules in Analytic Function Spaces,
Tsinghua Sanya International Mathematics Forum (TSIMF), May 26, 2017.
Homogeneous bundles and operators in the Cowen-Douglas class, International Workshop on Operator Theory and its Applications (IWOTA), East China Normal University, Shanghai,
July 26, 2018.
The Berger-Shaw theorem for a pair of commuting operators, Hilbert Modules in Analytic Function Spaces, Tsinghua Sanya International Mathematics Forum (TSIMF), Dec 30, 2019.
Spherical Operators, School of Mathematics 120th anniversary of the Hebai normal university, May 21, 2022.
Invariant subspaces of the L2 space of the disc, 
Joint Spectra and related Topics in Complex Dynamics and Representation Theory, BIRS, Banff, May 21 - May 26, 2023.
Institute for Mathematical Sciences, Chennai, 1987
International Workshop on invariant subspaces, University of Delhi,
1987
Mehta Research Institute, Allahabad, 1987
Mehta Research Institute, Allahabad, 1989
Discussion meeting on Harmonic Analysis, IIT - Kanpur, 1990
Discussion meeting on Harmonic Analysis, IISc., Bangalore, 1992
Annual meeting, Indian Mathematical Soc., University of Poona,
Pune, 1994
Central University, Hyderabad, 1996
Discussion meeting on Harmonic Analysis, ISI - Calcutta, 1998
Ramanujan Mathematical Society, Thirunelvelli, 1998
Workshop on Dynamical Systems and Ergodic Theory, Mumbai, 1999
Millenium Lectures on Functional Analysis, IIT-Gwauhati, 1999
Discussion meeting on Harmonic Analysis, IIT - Kanpur, 2000
International Workshop on functional Analysis,
Cochin University of Science & Technology, August 2001
Annual Meeting of the Jammu Mathematical Society, February 2002
International Conference on Harmonic Analysis and Quantum groups,
Cochin University of Science & Technology, January 2005
Indian Institute of Science, February 2006
Institute of Physics, Bhubaneswar, September 2006
Homogeneous operators on Hilbert spaces of holomorphic functions, Colloquium, Indian Institute of Science, Mar 2006.
Institute for Mathematical Sciences (IMSc), Chennai, August 2007
Discussion Meeting on non-commutative geometry and operator algebras, Feb 2008
Ramanujan Institute for Advanced Study in Mathematics, Mar 2008
Ramanujan Mathematical Society, Plenary talk
Annual Meeting, IIT - Kanpur, May 2008.
Kerala University, Dec 2008
IISER Pune, October 2009
Kerala School of Mathematics, Calicut, Feb 2010
Conference on Mathematical Foundations of Quantum Mechanics
IISER Kolkata, December 2010
Counting, INSPIRE, KIIT Bhubaneswar, January 14 and July 22, 2011.
Differentiation (?)!, Institute Colloquium (IISc), April 15, 2011.
Computing $\pi$, KVPY-11, IISER Trivandrum, June 21, 2011, 2011.
A tale of two hotels, INSPIRE, HNB Garhwal University, Srinagar Garhwal, November 12, 2011.
IIT, Chennai, Dec 22, 2011
Curvature Inequalities, 
SunderFest, IMSc, April 4 - Apr 6, 2012.
Delhi University, August 2012
Almora Mathematical Surveys, Almora, Sep 2012
Ramanujan Mathematical Society, Plenary talk
Annual Meeting, New Delhi, Oct 2012
Recent advances in Operator Theory and Operator Algebras
Indian Statistical Institute, Bangalore, Jan 2013
Quasi-invariant kernels, First Department Day, IISER - Kolkata, March 14 - 15, and Colloquium, IISER Pune, Sep 13, 2013.
Zeroes of polynomials, Science Academies Lecture workshop, Jain University, Bangalore, December 28, 2013.
The Bergman kernel and the Bergman metric, Recent Advances in Operator Theory and Operator Algebras, Indian Statistical Institute, Bangalore, December 15, 2014.
Homogeneous Vector Bundles and intertwining
Operators for Symmetric Domains, Geometry of Banach Spaces and Operator Theory, March 27, 2015.
Curvature Inequalities for operators in the Cowen-Douglas class, Annual Conference of the RMS, IISER Mohalli, May 15, 2015, and also at MSI Belgaum, Feb 27, 2022.
Ethics in Science – the dos and don'ts and a short video clip from Nature: Reproducibility Crisis, SRFP 2016 - Special Lecture (Indian Academy of Sciences), June 17, 2016.
The bound of Varopolous and embedding of $\ell^1(n)$, Calcutta Mathematical Society, Dec 17 - 19, 2015 and Ramakrishna Mission Vidyamandir, September 27, 2016.
Role of the curvature in Operator theory, IIT Kanpur, December 14, 2016.
Grothendieck Inequality, R.K. Rubugunday Distinguished Lecture, Chennai Mathematical Institute (CMI), January 18, 2017.
The Polynomial Game and the Cantor Set, Pi Day, IISER Pune, March 11, 2017.
Fundamental Theorem of Calculus, IIT Dharwad, April 12, 2018.
Homogeneous Hermitian holomorphic vector bundles and the Cowen-
Douglas class over bounded symmetric domains, Somesh Chandra Bagchi Memorial Lecture, Sep 11, 2018
Grothendieck Inequality, Colloquium, ICTS, Bangalore, April 22, 2019.
The Bergman Kernel, Research Scholars Meet, Jammu University, August 22, 2019.
The Arveson-Douglas conjecture for semi-submodules, Conference on Functional Analysis @ IIT Bomby 2019, October 19, 2019.
A product formula for homogeneous
characteristic functions, Plenary Lecture, Indian Mathematical Society, IIT Kharagpur, November 22, 2019.
Advanced Functional Analysis and its Applications, IIT Hyderabad, November 25 - 29, 2019.
Berger-Shaw Theorem,
KBSFest, ISI Bangalore, December 13, 2019.
1+2+3 + ... = - 1/12, Gujarat University, December 22, 2019.
Real stability of polynomials, IIT Kanpur, December 25, 2019.
Science of Indias’ Tomorrow,
ANNIVERSARY MEETING, NIO Goa, INSA Dec 16 -18, 2019,
and Sushil Kumar Banerji Memorial lecture, Indian Statistical Institute, Kolkata, February 28, 2020.
Which homogeneous operators are subnormal, , Punjab University, Feb 14; IISER Bhopal Math Symposium, Mar 6, and WOTOA, Aug 26, 2020.
Mathematics of everything, Pre-Event of IISF 2020, CSIR-CSMCRI, Bhavnagar, Dec 18, 2020.
Determinant of an operator , IIT Kharagpur, Mar 03, 2021.
The euclidean ball and the polydisc, , Ramakrishna Mission Centenary college, October 8, 2021
Games that mathematicians play, , Netaji Subhas Open University, November 27, 2021
Ahlfors' Schwarz Lemma, Mathematical Sciences Institute Belgaum, Feb 25, 2022.
Arnold's proof of the nonexistence of a solution to the quintic equation, Identity, Maths Club of IISER Kolkata, Feb 25, 2022.
Around the Schwarz Lemma , AIS Lectures, May 26, 2022.
Curvature Inequalities , AIS Lectures, May 27, 2022.
Biholomorphic inequivalence of the euclidean ball and the poly-disc , AIS Lectures, May 28, 2022.
Unstacking, Conway’s soldiers and Fibonacci numbers, Mathematics Department Colloquium BITS Pilani, K K Birla Goa Campus
January 31, 2023.
Mackey Imprimitivity and commuting tuples of homogeneous normal operators, Bhagavatula Ramamurthy & Bhagavatula Saradamba Memorial Lecture, University of Hyderabad, March 07, 2024 and Ashoka University, April 02, 2024.