The President of India is the Supreme Commander of the Indian Armed Forces. President of India is also the formal head of all the three branches of Indian Democracy - Legislature, Executive and Judiciary. Powers to pardon and clemency vests with the President of India.
The President is elected, from a group of nominees, by the elected members of the Parliament of India (Lok Sabha and Rajya Sabha) as well as of the state legislatures (Vidhan Sabhas), and serves for a term of five years. Historically, ruling party (majority in the Lok Sabha) nominees have been elected and run largely uncontested. Incumbents are permitted to stand for re-election. A formula is used to allocate votes so there is a balance between the population of each state and the number of votes assembly members from a state can cast, and to give an equal balance between State Assembly members and National Parliament members. If no candidate receives a majority of votes there is a system by which losing candidates are eliminated from the contest and votes for them transferred to other candidates, until one gains a majority. The Vice-President is elected by a direct vote of all members (elected and nominated) of the Lok Sabha and Rajya Sabha
Source: wikipedia