India has nearly 250,000 eligible voters over the age of 100 and about 18 million over 80, the country’s chief election commissioner said on Thursday.
More than 910 million people are registered to vote in the country, which has a population of about 1.4 billion.
India holds state assembly ballots and national elections that pose logistical challenges and incur high costs.
Rajiv Kumar, who leads the country's election commission, praised the older generation of voters on Wednesday at a rally in Pune city, in the western state of Maharashtra.
The event was held to raise awareness about registration as part of a summary revision of the city's voter list.
"You will be happy to know we have close to [249,000] voters on our rolls who are 100-plus and what a relief and ecstasy it gives you when you interact with them and find that they have been voting all through their lives," he said.
Summary revisions are held annually to add eligible citizens to the list.
Mr Kumar said this year's initiative would focus on increasing the number of registered voters in urban areas.
From the remotest parts of the country in the Himalayas to the coastlines, citizens get the right to cast their votes in elections in what is often called the “festival of democracy”.
India granted all citizens over the age of 18 the right to vote in 1949, when the constitution was enacted.
Shyam Saran Negi was the first to cast his ballot in India's inaugural general election in 1951. He died this month at the age of 106.
Negi, from a remote village in the northern state of Himachal Pradesh, used a postal vote on November 2, three days before his death, to participate in state elections.
Negi was 31 when India gained independence from Britain and never missed a vote. He was the brand ambassador for the Election Commission.
In recent years, overall voter turnout in India has dropped sharply, with turnout particularly low among young people.
Many of those registered to vote at polling places in remote areas find it difficult to return to cast a ballot because they study and work in cities.
“Be it hills, coastal lines, inaccessible terrains, deserts, everywhere, every single citizen gets enlisted as a voter and strengthens the democracy by getting registered. This indicates the robustness and beauty of the country’s electoral rolls,” Mr Kumar said.
India conducted assembly elections in three states this year.
Votes in Himachal Pradesh and Gujarat — states with strong support for the ruling Bharatiya Janata Party — are scheduled for November 12 and the first week of December, respectively.