The Congress high command had suspended legislator Sudip Roy Barman who led the five disgruntled legislators.
Former Tripura chief minister Samir Ranjan Barman along with six rebel Congress legislators, including his son Sudip will join Trinamool Congress after the end of Ramazan next month.
"I along with five other Congress MLAs and my father, former chief minister Samir Ranjan Barman, will join Trinamool Congress after the end of Ramazan next month," Sudip Roy Barman told news agency PTI.
"We want to fight the Assembly election in Tripura under the leadership of Mamata Banerjee. In Tripura, Congress has lost all credibility after it entered into an alliance with CPI(M) in West Bengal. How can you fight against CPI(M) when you have an alliance with them in another state ?" he said.
The development comes a day after Trinamool Congress general secretary Mukul Roy held a closed-door meeting in Agartala with the six rebel Congress legislators of Tripura to explore the possibility of inducting them into the party.
The legislators whom Mr Roy met had fallen foul of the Congress high command after they criticised the party leadership for entering into a tie-up with the Left in West Bengal saying it reflected badly on the party's position as the principal opposition party in Tripura.
The Congress high command had suspended legislator Sudip Roy Barman who led the five disgruntled legislators.