However, voters who were in the queue at 6 p.m. will be allowed to vote.
According to Chief Electoral Officer, Tamil Nadu, Satyabrata Sahoo, the polling in Vikravandi and Nanguneri was peaceful and brisk. About 76 per cent polling was recorded in Vikravandi, and 62 per cent in Nanguneri till 5 p.m.
The bypoll in Vikravandi was necessitated following the death of DMK legislator K. Rathamani in June, while the Nanguneri seat fell vacant after Congress legislator H. Vasantha Kumar got elected to the Lok Sabha and resigned.
A total of 35 candidates are in the fray in the two seats.
In Vikravandi, some 23 candidates are seeking the favour of about 2.24 lakh voters.
The main fight is between ruling AIADMK's R. Muthamilselvan and DMK's N. Pugazhenthi.
In Nanguneri, about 2.57 lakh voters were eligible decide the fate of 12 candidates, though the main fight between AIADMK's V. Narayanan and Congress candidate Ruby R. Manohar.
Security was beefed up in the two constituencies for the peaceful conduct of the polls.
According to reports, about 20,000 voters in Nanguneri boycotted the polls demanding the removal of Devandra Kulla Vellalar caste from the Dalit list.
While campaigning for his party candidate in Vikravandi, Naam Tamilar Katchi (NTK) leader Seeman started a controversy when he justified former Prime Minister Rajiv Gandhi's gruesome killing for sending the Indian Peace Keeping Force (IPKF) to Sri Lanka.
Seeman said history will be rewritten in the future to the effect that Rajiv Gandhi, who had sent the IPKF to Sri Lanka to kill Tamil, was later murdered in the Tamil land.
A female suicide bomber of the Liberation Tigers of Tamil Eelam (LTTE) blew herself up at an election rally near Chennai killing the former Prime Minister on May 21, 1991.
Seeman was booked by the Tamil Nadu Police for making the provocative speech with an intention to cause riots and breach peace.
In the 234-member Tamil Nadu Assembly, the ruling AIADMK has 123 members (including the Speaker), the DMK 100, Congress 7, IUML and Independent have one each and two seats are vacant.
In the Union Territory of Puducherry, nine candidates are in the bypoll fray but the main contest is between Congress party's A. John Kumar and AINRC nominee S. Bhuvaneswarane.
The bypoll in Puducherry became a necessity after Congress legislator V.Vaithilingam was elected to the Lok Sabha in April this year.
The counting of votes will take place on October 24.
( With inputs from IANS )