What is the name of the first president of India?

The first President of the independent Republic of India was Rajendra Prasad. He first became president in 1950, and served in this position for twelve years, until a year before his death in 1963. He was re-elected in 1952, and again in 1957, an achievement that remains unsurpassed to this day.
Born in 1884 in Bihar province, Rajendra Prasad quickly established himself as a highly intelligent young boy. While still a student he became deeply involved in politics; at this time a growing Indian Nationalist movement was developing to challenge British imperial rule. After graduating, however, Prasad followed a more traditional career path, becoming first a Professor of English at a college, and then later a very successful lawyer.
It was while working as a lawyer that Prasad became more closely involved with the nascent Indian Nationalist movement. He met Gandhi, and was highly impressed both with his ideas and his demeanor. Indeed, Gandhi made such an impression on Prasad that he gave up his lucrative law practice to participate in the campaign of mass civil disobedience against British rule begun by the Mahatma. But Gandhi's influence on Prasad extended beyond mere politics. Prasad began to adopt the kind of ascetic lifestyle made famous by Gandhi, a far cry from his previous life as a member of India's educated elite.
Over the years, Prasad's involvement with politics deepened further. He was elected President of the Indian National Congress in 1934, and subsequently played a key role in Gandhi's anti-imperialist "Quit India" campaign. Not long before independence was finally granted, Prasad briefly served as a minister in the interim government of Jawaharlal Nehru, who would go on to become the first Prime Minister of the newly independent India.
Prasad was a leading figure in the framing of the Indian Constitution, a task he combined with his formal role as President of the Constituent Assembly. Then, in 1950, Rajendra Prasad became the first President of the Republic of India. The role was, and is, largely that of a non-partisan figurehead. The President of India does not have executive power in the same sense as the President of the United States, for example.
President Prasad became an ambassador for the newly independent state, touring the world and making important diplomatic connections with other countries. He was the public face of India, and his obvious intelligence, congeniality, and wisdom endeared him to many.
Rajendra Prasad passed away in 1963, not long after receiving the Bharat Ratna, India's highest civilian award and equivalent to the Presidential Medal of Freedom in the United States. The award of this great honor showed the enormous esteem in which Prasad was widely held, an esteem which still persists to the present day.
https://www.indiatoday.in/fyi/story/presidential-elections-rajendra-prasad-president-twice-congress-sarvepally-radhakrishnan-1022967-2017-07-07