Former home minister Zail Singh, a loyal follower of Prime Minister Indira Gandhi, won an overwhelming victory today as India's next president.

Singh, 66, defeated the opposition candidate, former Supreme Court judge H. R. Khanna, winning 73 percent of the votes in indirect balloting by India's state and national legislators. The voting took place Monday and ballots were counted today.

Singh's vote exceeded the two-thirds majority that Gandhi's Congress-I party holds among the legislators who cast ballots, indicating that opposition members broke ranks to support him.

His overwhelming victory was widely interpreted here as a sign of Gandhi's strength.

While the president is largely powerless, he is the commander in chief of the military and bears the responsibility of deciding who should form a new government after a parliamentary no-confidence vote.

According to political sources here, Gandhi mobilized her party whips in state legislatures to bring out a heavy vote for Singh, who is the first member of the small but prominent Sikh religion to be president of India.

Singh will be sworn in on July 25 as India's seventh president, succeeding N. Sanjiva Reddy, whose five-year term is expiring.