Congress on Monday retained the Liromoba Assembly seat with its candidate Nyamar Karbak defeating his BJP rival by a slender margin of 119 votes.
While Mr. Karbak polled 3,808 votes, BJP nominee Bai Gadi polled 3,689 votes followed by Independent candidates Lijum Ronya (2,589), Lijum Ronya, Raksap Yomcha (355) and Johny Tali (40 votes).
Nine voters also opted for NOTA, deputy chief electoral officer D J Bhattacharjee said.
Bypolls was necessitated due to the death of former Chief Minister Jarbom Gamlin on November 30 last year.
With the win, the Congress in the state has 47 MLAs in a 60-member House while opposition BJP has 11 legislators and two independents.