Luizinho Faleiro was elected to the Rajya Sabha unopposed in a by-poll, according to a notification of the West Bengal Assembly.
Faleiro, the former chief minister of Goa, had quit the Congress and joined the TMC in September.
In Goa, the Congress and the TMC are engaged in a pitched battle with West Bengal Chief Minister Mamata Banerjee calling out all opposition parties to join hands.
Goa elections: Will TMC's re-entry in state with ex-CM Faleiro's induction alter its political landscape?
TMC is likely to be formally announced its official entry into Goa politics on Monday with Faleiro scheduling a press meet.
Faleiro joined the TMC on Wednesday in Kolkata along with nine other leaders.
He joined the party in presence of TMC general secretary Abhishek Banerjee and other senior leaders such as Sougata Ray and Subrata Mukherjee.
He was received at Dumdum airport by senior TMC leaders, West Bengal minister Sujit Bose and Rajya Sabha MP Santanu Sen.
The Congress veteran resigned as an MLA and as a primary member of Congress on Monday and said the Goa party unit was run by a "coterie of leaders who prioritise only self-interest".
Goa leader Luizinho Faleiro’s exit has again brought the focus on the Congress’s failing to address the in-house issues.
Faleiro resigned as MLA of Navelim and as a primary member of Congress alleging that the state party unit is being run by a "coterie of leaders who prioritise self-interests".
'Absolutely no hope or will to prevent collapse of party': Ex-Goa CM Luizinho Faleiro quits Congress
In his letter to Sonia Gandhi, Luizinho Faleiro said 'it (the party) is functioning contrary to every ideal and principle of its founding fathers upheld by Indiraji, Rajivji and you (Sonia Gandhi)'.
With his resignation, INC's strength in the 40-member House has been reduced to four.
Amid rumours of him joining the Mamata Banerjee-led party, Faleiro has called a press conference on Monday where he would make an "important announcement."