Ruling BJP-backed candidate, Ram Nath Kovind, a former lawyer from the low-caste Dalit community, is expected to win the presidency in an election seen as tightening PM Narendra Modi's grip on power.
India's parliament voted on Monday for a new president in an election likely to be won by a candidate backed by the ruling Bharatiya Janata Party (BJP).
Ram Nath Kovind's likely ascent to the highest public office is expected to tighten Prime Minister Narendra Modi's grip on power.
Kovind's election as president would be the first by a leader who started out with the Rashtriya Swayamsevak Sangh, or National Volunteers' Association, a Hindu nationalist mentor of the BJP and its affiliates.
Kovind, 72, is a former lawyer from the low-caste Dalit community.
He is facing Meira Kumar, a former parliament speaker and a fellow-Dalit backed by the opposition Congress party.
The result will be announced on Thursday but Kovind's victory is almost certain since the BJP says it has the electoral college numbers needed to push its candidate through.
Some 4,900 legislators nationwide voted in what Modi termed a "historic" election to choose India's head of state.
Modi, among the first to cast his vote in parliament, said he looked forward to working with Kovind.
"My government will offer full cooperation to him," he told members of parliament from the ruling coalition.
Voted in the Presidential elections 2017. pic.twitter.com/2EttGVwwhs— Narendra Modi (@narendramodi) July 17, 2017
The president's role is largely ceremonial but as the custodian of the constitution, the president has played an important role in times of uncertainty, such as when a general election is inconclusive and a decision has to be made about which party is best placed to form a government.
Some presidents, such as outgoing President Pranab Mukherjee, have tried to act as conscience-keepers, using their constitutional authority as the head of state to defend India's founding principles as a secular, diverse democracy.
Modi's rivals say minority Muslims have feared for their wellbeing and have been targeted by fringe Hindu groups since he took office in 2014.
Sonia Gandhi, the head of the Congress party, appealed to members of parliament to vote for Kumar to protect India's secular values.
"We cannot and must not let India be hostage to those who wish to impose upon it a narrow-minded, divisive and communal vision," she said.