The ruling TRS party had earlier declared support to NDA nominee Ram Nath Kovind in the election. The TRS members arrived at the Assembly in a bus from their party office.
The party yesterday conducted a meeting of its MLAs to familiarise them with the voting procedure.
The value each MLA's vote in Telangana is 132.
The authorities have made elaborate arrangements for the election.
The opposition's nominee for the top constitutional post is former Lok Sabha Speaker Meira Kumar.
In the 119-member Telangana Legislative assembly, excluding a nominated member who doesn't have voting right in the presidential election, the ruling TRS has a strength of 82, followed by Congress (19), MIM (7), BJP (5), TDP (3), CPI (1), CPI-M (1) and Independent (1).
There are 16 Lok Sabha members and 10 Rajya Sabha members from Telangana.
Noting that Meira Kumar was the Lok Sabha speaker when the Andhra Pradesh Reorganisation Bill (for the formation of Telangana) was passed, the Congress had earlier said all electors in Telangana should vote for her as an expression of gratitude.