Senior tribal leader Diba Chandra Hrangkhawl was on Monday chosen as leader of Trinamool Congress Legislature Party in Tripura Assembly.
His name was announced by TMC leader Mukul Roy.
Hrangkhawl was among the six Congress MLAs had joined the party in June.
The MLAs, led by former opposition leader Sudip Roy Barman, had resigned from Congress in April and joined TMC in June to protest against the alliance between Congress and CPI(M) in West Bengal ahead of the state Assembly elections.
Tripura Speaker Ramendra Chandra Debnath had recently said the MLAs ould be recognised as TMC legislators and would not come under the Anti-Defection Act.