Post-poll surveys by independent local agencies have pointed to the CPM-led Left Front winning comfortably in Tripura.
But analysts have found it hard to read the trend in Meghalaya, where no party has managed a simple majority in decades, and Nagaland, where the Congress and the ruling Naga People's Front (NPF) have been on an almost equal footing in the past two assembly elections.
The 2008 election in Tripura saw the Manik Sarkar-shepherded Left Front bag 49 seats while the Congress won 10 and its indigenous tribal ally Nationalist Party of Twipra won 1.
In Meghalaya that year the Congress got 28 seats, the NCP 15 while regional parties won the rest.
Political instability saw the NCP first forming a government in alliance with regional parties, which walked out a year later to join a Congress-led alliance.
In Nagaland in 2008, the NPF defied predictions to win 26 seats compared to the Congress' 23, and continued with the NDA-backed Democratic Alliance of Nagaland government.
Through half the term, all the allies merged with the NPF, taking its tally in the 60-member House to 35.