The third phase of India's staggered general election will take place on Tuesday, with voters in 116 parliament constituencies across 15 states set to take part.

Among the states taking part in the third stage are Kerala and Gujarat, the latter being Indian Prime Minister Narendra Modi's home state and where he was the chief minister from 2001 to 2014.

The opening phase of the mammoth exercise was held on April 11 when about 139.7 million people, including differently abled and transgender people, had cast their votes.

In the second round, millions had again cast their votes across 95 constituencies, albeit amid violence and protests.

Polls had also taken place in the restive Indian-occupied Kashmir (IOK), where authorities had to deploy tens of thousands of security forces.

With 900 million of India's 1.3 billion people registered to vote, it is the world's largest democratic exercise. Over the course of the election, 543 Lok Sahba seats will be decided from about a million polling stations across India.

Votes will be counted on May 23 and the results are expected the same day.

Modi and his Bharatiya Janata Party (BJP) have run an aggressive campaign, playing to their nationalist, Hindu-first base and attacking rivals they accuse of appeasing minorities.

Critics say such divisive election rhetoric is a threat to India's secular foundations.

The Congress party, meanwhile, has focusing on concerns about rising unemployment and agrarian distress and is staking it campaign on a promise for a generous handout to India's poorest families.

It is trying to rebuild its appeal after winning only 44 seats in 2014 and has promised monthly handouts of 6,000 rupees ($86.59) for the poorest families.

It hopes to win enough seats to lure regional parties opposed to Modi after the election and form the government.