The result will be declared on December 24.
The dates have been announced three days after the Madras High Court gave a December 31 deadline for the election of a new lawmaker for the constituency.
The election for RK Nagar, which Jayalalithaa represented for two terms, was cancelled earlier in April following allegations of a massive amount of cash and other inducements being circulated among voters. The Election Commission was told that voters were being bribed with prepaid phone recharge coupons, newspaper subscriptions, milk tokens and mobile wallet payments. A minister was also accused of arranging such inducements. A video showing Rs 4,000 cash being handed to voters went viral.
Chief Election Commissioner Nasim Zaidi said the commission was looking at how it can devise a more effective strategy against bribing of voters, pending legislation. "I think that assessment will be completed soon and the Commission will take a call," Mr Zaidi told news agency IANS.
The opposition DMK has alleged in court that one lakh fake voters were registered in the constituency and said there should be no voting till corrections are made. The Election Commission removed 45,000 names, after which the High court ordered a deadline for the polls.
Sasikala's nephew TTV Dhinakaran had announced that he would contest the election as the candidate of the AIADMK. But Dhinakaran has been sidelined by Chief Minister E Palaniswami and Paneerselvam, who merged his rebel faction into the party in August on the condition that Sasikala would no longer be its chief.
"Certainly I'd win after the governing council nominates me for RK Nagar. There's a situation we are required to fight and reclaim the two-leaves symbol," Dhinakaran said.
Sasikala is serving a four-year jail term for corruption.
The by-election, being held after the two-leaves symbol of AIADMK was restored to the E Palaniswami-Panneerselvam group - referred to as EPS-OPS camp - is being seen as a test for the united AIADMK and the faction headed by Sasikala. Many also see it as a referendum on the performance of the EPS government.