| Sl.No. | Institution | Position | Year |
| 1 | State University of New York, Albany, New York, USA | Post Doctoral Fellow | March 1981-August 1981 |
| 2 | University of California, Riverside, California, USA | Lecturer | September 1981-June 1982 |
| 3 | Max Planck Institute for Quantum Optics (Theory Group), Munich , Germany | Research Associate | July 1982-November 1983 |
| 4 | University of Notre Dame, Notre Dame, Indiana, U SA | Research Associate | December 1983-July 1984 |
| 5 | Colorado State University, Fort Collins, Colorado, USA | Assistant Professor | August 1984-May 1987 |
| 6 | Utah State University, Logan, Utah, USA | Assistant Professor | September 1987-June 1990 |
| 7 | Oxford University, Oxford, UK | Fellow(Level of Lecturer) | October 1990-June 1991 |
| 8 | Indian Institute of Technology, Bombay, INDIA | Associate Professor | July 1991-December 1992 |
| 9 | Oxford University, Oxford, UK | Fellow (Level of Lecturer) | January 1993-June 1993 |
| 10 | Indian Institute of Astrophysics, Bangalore, India | Professor | July 1993-March 2002 |
| 11 |
Indian Institute of
Astrophysics, Bangalore, India |
Senior Professor |
April 2002-June 2014 |
| 12 |
Indian Institute of
Astrophysics, Bangalore, India |
Acting Director |
July 2012-July 2013 |
| 13 |
Indian Institute of
Astrophysics, Bangalore, India |
Distinguished Professor |
July 2014-Present |
| Sl.No. | Institution | Position | Year |
| 1 | International Centre for Theoretical Physics, T rieste, Italy | Guest Scientist | June-October 1982 |
| 2 | Clarendon Laboratory and Theoretical Chemistry, Oxford University, UK | Visiting Fellow | January-February 1983 |
| 3 | Clarendon Laboratory, Oxford University, UK | Visiting Fellow | May-August(Summer) 1985 |
| 4 | Clarendon Laboratory, Oxford University, UK | Visiting Fellow | May-August(Summer) 1986 |
| 5 | Clarendon Laboratory, Oxford University, UK | Visiting Fellow | May-August(Summer) 1987 |
| 6 | Technical University, Delft, Holland | Visiting Fellow | July-September(Summer) 1987 |
| 7 | University of Washington, Seattle, Washington, USA | Visiting Faculty | June-August(Summer) 1988 |
| 8 | Clarendon Laboratory, Oxford University, UK | Visiting Fellow | December 1988-January 1989 |
| 9 | Institute for Theoretical Atomic and Molecular Physics, Harvard University | Visiting Fellow | July 1989 |
| 10 | University of Florida, Gainesville, USA | Visiting Faculty and Member | June-September(Summer) 1990 |
| 11 |
National Institute for
Nuclear Theory, University of Washington, Seattle |
Visiting Scholar |
July 1995 |
| 12 |
National Institute for
Nuclear Theory, University of Washington, Seattle |
Visiting Scholar |
July 1999 |
| 13 |
Johannes Guetenberg
Universitaet, Mainz,Germany |
Visitor |
October 2000 |
| 14 |
Johannes Guetenberg
Universitaet, Mainz,Germany |
Visitor |
October 2002 |
| 15 |
Eotvos Lorand
University, Budapest,Hungary |
Visitor |
July- August 2003 |
| 16 |
National Institute for Nuclear Theory, University of Washington, Seattle | Visiting Scholar |
October- November 2002 |
| 17 |
GSI, Darmstadt, Germany |
DAAD |
May 2005 |
| 18 |
University of
California, Berkeley |
Visiting Scholar |
March- April 2006 |
| 19 |
University of
California, Berkeley |
Visiting Scholar |
March- April 2007 |
| 20 |
Institute for
Theoretical Atomic and Molecular Physics Harvard University |
Visitor | May 2007 |
| 21 |
National Institute for Nuclear Theory, University of Washington, Seattle | Visiting Scholar | July 2008 |
| 22 |
Eotvos Lorand University, Budapest,Hungary | Visiting Professor | May 2009 |
| 23 |
Tohoku University,
Sendai, Japan |
JSPS Fellow |
May 2012 |