He served as the MLA of the Tripura Legislative Assembly from the Agartala constituency which he held since 1998 by winning four elections consecutively on INC ticket by handsome margins.
[2] During his college days, Barman was actively involved with NSUI, the Students Wing of the Indian National Congress.
Barman contested assembly election for the first time in 1993 from Agartala constituency against former CPI(M) Chief Minister Nripen Chakraborty and lost.
He won 5 assembly elections consecutively since 1998 defeating prominent Communist leaders Dr Bikash Roy, Sankar Prasad Datta, Krishna Rakshit respectively.
[3] On 7 August 2017, he along with 5 other AITC MLAs of Tripura Legislative Assembly joined BJP in presence of Himanta Biswa Sarma and Dharmendra Pradhan after they cross voted against the party lines in 2017 Indian presidential election.