The lawmaker met KCR at the TRS chief's farmhouse at Erravelli near Hyderabad, according to reports.
Congress in Telangana continued to face desertions ahead of Lok Sabha elections as one more MLA and a party functionary Sunday announced their decision to leave the party and join the ruling TRS.
Vanama Venkateswara Rao, representing Kothagudem, announced his support to the TRS president and Chief Minister K Chandrasekhar Rao.
He becomes the eighth Congress lawmaker to shift sides, which had won 19 seats in the December 7 elections to the 119-member Telangana Assembly.
Separately, Telangana Pradesh Congress Committee (TPCC) SC cell chairman Arepalli Mohan joined TRS in the presence of TRS working president K T Rama Rao, TRS sources said.
Venkateswara Rao said he would quit the assembly membership "if necessary".
"All-round development of Kothagudem constituency is important to me. KCR ji has assured me to comprehensively develop it," he said in a statement.
TRS sources said the lawmaker met KCR at the TRS chief's farmhouse at Erravelli near Hyderabad.
Earlier, Congress lawmakers Atram Sakku, Rega Kantha Rao, Haripriya Naik, Ch Lingaiah, P Sabita Indra Reddy, D Sudhir Reddy, Upender Reddy had announced their decision to shift to the TRS.
The desertion of the lawmakers is seen as a setback to the Congress in the run-up to the Lok Sabha elections.
It would lose the status of main opposition in the 119-member House if the eight lawmakers go ahead with their decision to resign.
The party requires minimum 12 MLAs, being 10 per cent of the house strength to retain the principal opposition status.
If four more Congress MLAs join the dissidents, the group will not attract provisions of anti-defection law.
TRS scored a thumping win in the assembly elections winning 88 seats.
Congress has accused the TRS of encouraging defection of its lawmakers and said it would meet the state Governor besides launching a campaign against the ruling party.
Congress Legislature Party (CLP) leader M Bhatti Vikramarka had in a recent statement alleged the Chief Minister was "conspiring to eliminate the opposition as he lacked courage to answer their questions".