Ruling AIADMK nominee P Saroja, the widow of C Perumal is crossing swords in a keenly contested battle with DMK candidate V Maran.
Nine Independents are also testing their electoral luck from the constituency.
This is the fourth bypoll being held in Tamil Nadu since 2011 after AIADMK returned to power and the ruling dispensation had won all the three.
Chief Minister Jayalalithaa has deployed all her ministers to ensure the party candidate's victory.