A candidate for the office of the President of India must be proposed by-

The correct answer is 50-50.

Key Points

According the Constitution of India the nomination of a candidate for election to the office of President must be subscribed by at least 50 electors as proposers and 50 electors as seconders.
A candidate to be nominated for the office of president needs 50 electors as proposers and 50 electors as seconders for his name to appear on the ballot.
A candidate shall not be deemed to be duly nominated for election unless he deposits or causes to be deposited a sum of fifteen thousand rupees.
Provided, that where a candidate has been nominated by more than one nomination paper for the same election, not more than one deposit shall be required for him under this sub-section.
Additional Information

Article 58 of the constitution sets the principal qualifications one must meet to be eligible to the office of the president.
A president must be:
a citizen of India
of 35 years of age or above
qualified to become a member of the Lok Sabha.
Article 57 provides that a person who holds, or who has held, office as President shall, subject to the other provisions of this constitution, be eligible for re-election to that office. Under the Presidential and Vice-Presidential Elections Act, 1952