B. Prakash, J. Santosh Kumar and AB. Lingaiah Yadav were elected to the Upper House. Congress candidate and former union minister P. Balram Naik was defeated, officials said.
A total of 108 members of the Assembly voted. Mr Prakash secured 33 votes while Santosh Kumar and Mr Yadav polled 32 votes each. The Congress candidate got only 10 votes as independent member D. Prakash Reddy's vote was declared invalid by the Election Commission.
The poll panel took the decision after the complaint by the Returning Officer that Prakash Reddy showed his vote to the Congress agent before casting it.
The election became inevitable after the Congress fielded a candidate though the TRS had comfortable strength in the 119-member Assembly to win all three seats.
The TRS has 91 lawmakers while the Majlis-e-Ittehadul Muslimeen (MIM), which has seven members, also supported the ruling party.
The Bharatiya Janata Party (5 members), Telugu Desam Party (2 members) and Communist Party of India-Marxist (1 member) abstained from voting.
Two Congress members -- Komatireddy Venkat Reddy, S.A. Sampath Kumar - could not vote as they were expelled from the House last week for allegedly hurling headphones during the Governor's address, injuring Legislative Council Chairman Swamy Goud in his eye.