Over 2,660 booths have been identified as sensitive and over 45,000 security personnels have been deputed in these five constituencies.
Over eight million voters including 3.7 million women voters are expected to decide the fate of 81 candidates who are in the fray.
Maximum of 22 candidates are contesting from Tonk-Sawai Madhopur constituency and the lowest of 12 from Bharatpur Lok Sabha seat.
India's former cricket captain Mohammad Azharuddin, union Minister's Namonarain Meena and Jitendra Singh of the Congress and Harish Meena, former director general of police, and Mahant Chandnath of the BJP, and Kirodi Lal Meena of National People's Party are some of the main contestants.
In 2009 elections, the Congress had won 20 of the 25 Lok Sabha seats, BJP four and independent one.