Superintendent of Police (Police Control), Uttam Bhowmick, said the ultras led by self-styled lieutenant, Ganthachran Rupini surrendered before DSP, Ranabir Debbarma, at Bhandarima, a remote tribal hamlet in North Tripura district, yesterday.
They deposited two wireless sets during surrender.
The insurgents told interrogators that the outfit was facing financial difficulties.
Besides, frequent raids by Bangladeshi security forces in their camps are making it difficult for the outfit to use the foreign soil, Bhowmick said.