The remaining 10 seats will see polling April 17 and 24.
Bastar, which comprises six assembly segments, has more female voters at 665,290 than 633,681 male voters.
The main contest is between Bharatiya Janata Party nominee and sitting MP Dinesh Kashyap and Congress candidate Deepak Karma, son of late Mahendra Karma, the founder of the controversial Salwa Judum civil militia movement.
Aam Aadmi Party's Soni Sori, a tribal woman from the district now on bail after facing charges of acting as a conduit for Maoists, is also in the fray.
