Vote counting begins on Thursday, and the election result will likely be known the same day. Exit polls by two leading television news channels, Republic and TimesNow, projected a victory for Modi's Bharatiya Janata Party and its allies with 287 to 305 seats out of 543 — far ahead of the 272 seats needed to form the next government.
The election is seen as a referendum on Modi and his Bharatiya Janata Party. The BJP's main opposition is the Congress party, led by Rahul Gandhi, the scion of the Nehru-Gandhi dynasty that has produced three prime ministers.
Indians are voting in the seventh and final phase of national elections, wrapping up a 6-week-long long, grueling campaign season with Prime Minister Narendra Modi's Hindu nationalist party seeking reelection for another five years.
The voting on Sunday also covers Modi's constituency of Varanasi, a holy Hindu city where he was elected in 2014.
The election is seen as a referendum on Modi's five-year rule. He has adopted a nationalist pitch in trying to win votes from the country's Hindu majority by projecting a tough stance against Pakistan, India's Muslim-majority neighbor and archrival.
The Congress and other opposition parties are challenging him over a high unemployment rate of 6.1% and farmers' distress aggravated by low crop prices.
Counting of votes is scheduled for May 23.