In Tamil Nadu, nearly 7.54 lakh voters are expected to exercise their vote in by-polls.
The polling for three Tamil Nadu assembly constituencies -- Thirupparankundram, Aravakkurichi and Thanjavur -- and the lone Nellithope constituency in Puducherry began at 7 am on Saturday.
In Tamil Nadu, nearly 7.54 lakh voters are expected to exercise their vote and decide the fate of 81 candidates in the fray in the three constituencies.
In Aravakkurichi, ruling AIADMK's V Senthil Balaji will fight it out against the DMK's KC Palanisamy while at Thirupparankundram the AIADMK's AK Bose will take on the DMK's P Saravanan.
In Thanjavur, the AIADMK's M. Rengasamy is pitted against the DMK's Anjugam Bhoopathy.
In Thirupparankundram, the by-election has been necessitated by the death of AIADMK's legislator SS Seenivel.
While there are other parties in the contest, the contest is mainly between the AIADMK and the DMK in Tamil Nadu.
In Puducherry's Nellithope, Congress leader V Narayanasamy is contesting against AIADMK nominee Om Shakthi Segar.
The counting of votes will be held on November 22.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)