In the event of a vacancy created for the President's post due to death, resignation, impeachment, etc., Article 65 of the Indian Constitution says that the Vice President of India will have to discharge the duties. The Vice President reverts to office when a new President is elected and enters office. When the President is unable to act because of absence, illness or any other cause, the Vice President discharges the President's functions until the President resumes the duties.
A Vice President who acts as or discharges the functions of the President has all the powers and immunities of the President and is entitled to the same emoluments as the President.
The Indian Parliament has enacted the law (The President (Discharge of Functions) Act, 1969) for the discharge of the functions of the President when vacancies occur in the offices of the President and of the Vice President simultaneously, owing to removal, death, resignation of the incumbent or otherwise.
In such an eventuality, the Chief Justice, or in his absence, the senior most Judge of the Supreme Court of India available discharges the functions of the President until a newly elected President enters upon his office or a newly elected Vice President begins to act as President under Article 65 of the Constitution, whichever is the earlier.
