Ph.D. Department of Mathematics, University of Delhi, Delhi, 1997,
(Thesis title: The fuzzy subgroups of a group: their invariance, admissibility
and nilpotency, Supervisor : Professor K.C. Gupta)
M.Phil. Math Department of Mathematics, University of Delhi, Delhi, 1991.
M.A. Zakir Husain College, University of Delhi, Delhi, 1988.
B.A. - Math Zakir Husain College, University of Delhi, Delhi, 1986.
Pre-Univ.(Sc.) Cotton College, Guwahati, Assam, 1983.
H.S.L.C. Patacharkuchi Vidyapith, Bajali, Assam, 1980.
Professor, IIT Guwahati, since August 2009.
Associate Professor, IIT Guwahati, July 2004 - August 2009.
Assistant Professor, IIT Guwahati, April 1999 - July 2004.
Senior Lecturer, Gauhati University, July 1994 March 1999.
Lecturer, Cotton College Guwahati, June 1992 - July 1994.
Lecturer, Ramjas College, Delhi, September 1990 - June 1992.
International Congress of Mathematicians - 2006, Madrid, Spain, August 22-30, 2006.
Title of Contributed Talk: A characterization of a singular unicyclic graph.
AMS Sectional Meeting, Lincoln, Nebraska, USA, 21-23 October, 2005.
Title of Invited Talk: Corona of two graphs.
31st Annual Conference of Orissa Math. Society, Bhubaneaswar, 7-9 February, 2004.
Title of Invited Talk : Linear preservers of matrices.
Joint AMS-INDIA Meeting at IISc Bangalore, 17-20 December, 2003.