The party's tribal department chairman Phani Bhusan Bhowmik and general secretary Debabrata Koloi were among the 32 who sent their resignations to Congress president Sonia Gandhi.
The dissident tribal Congress leaders have fielded candidates in 21 assembly segments, including 18 seats reserved for tribals.
Last week, Congress general secretary Oscar Fernandes announced the nomination of 48 candidates for the state's 60-member assembly. Eleven seats were allocated to long-time ally INPT.
Of the 60 seats in Tripura, 20 are reserved for tribals and 10 for Dalits. Of the 30 reserved seats, the Congress-INPT alliance had won only one seat in 2008.
Meanwhile, Congress leaders and workers in 15 places in Tripura continued their revolt demanding changes in nominations for assembly elections.
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Tripura Congress president Sudip Roy Barman said the nominations would not be changed.
Meanwhile, despite the bickering between the Trinamool Congress and the Congress in West Bengal, the former will support the latter in the ensuing elections.
"We will not field candidates against the Congress. We don't want to split the non-Left votes," Trinamool Congress state chairman Arun Chandra Bhowmik told IANS.
Tripura, the country's lone Left-ruled state, is set for polling Feb 14. Meghalaya and Nagaland will go to the polls Feb 23. Results in all three states will be announced Feb 28.
The assemblies in Meghalaya, Tripura and Nagaland have 60 seats each.