As per the Indian Constitution, the President of India is the head of state and holds a highly prestigious position. The constitution defines the roles and responsibilities of the President, as follows:

• The President is the supreme commander of the armed forces and has the power to declare war or conclude peace, subject to the approval of the parliament.
• He appoints the Prime Minister of India, who in turn selects his Council of Ministers.
• The President has the authority to summon, prorogue, or dissolve either the Lok Sabha or the Rajya Sabha, or both, depending on the advice received from the Council of Ministers.
• The President also delivers the annual presidential address to the joint session of parliament outlining government policies and priorities.
• He can pardon or reduce the punishment of a convicted person, subject to the provisions and conditions set by the law.
• The President represents India in international relations, by sending and receiving diplomatic envoys and attending international meetings.
• In coordination with the Council of Ministers, he takes decisions on important policy matters like national security, social welfare, and economic development.

In conclusion, the president performs a vital role in maintaining the sovereignty of India by carrying out the duties entrusted to him under the Constitution of India.