About 65 percent of India's 900 million-strong electorate turned out over the six weeks of voting, the election commission said.
While the country faces a nerve-jangling three day wait until the official count begins, media polls after Sunday's final round said Modi's Bharatiya Janata Party (BJP) and its allies would secure enough seats to form a new government.
Modi, who fought an acrimonious campaign framed around his tough stance on national security, and other top BJP leaders made no immediate claim of victory.
As the vote drew to a close, the nationalist leader spent the weekend at a retreat in the Himalayas. He posted a Twitter picture of himself in a Hindu saffron robe looking out over the mountains.
Party spokesman G.V.L. Narasimha Rao said the polls "clearly show a huge positive vote for the leadership of Narendra Modi who has served the country with unmatched dedication.
"That people reward good performance has once again been proved by the overwhelming public mandate. This is a slap for the abusive opposition that made baseless charges and spoke lies," he added.
The BJP was not expected to match its landslide tally in 2014, which gave it enough seats to govern in its own right, but leading polls projected the ruling party and its allies winning between 282 and 313 seats of the 543 candidates elected to India's lower house.
Modi's alliance had 336 seats in the outgoing parliament.