when did he become the president?
21 July 1977
Neelam Sanjiva Reddy
Neelam Sanjiva Reddy was elected on 21 July 1977 and was sworn in as the sixth President of India on 25 July 1977.
who has been the only lok sabha speaker to have become the president of india Neelam Sanjiva Reddy
wiki:14116002
Neelam Sanjiva Reddy [SEP] President of India
Neelam Sanjiva Reddy was elected on 21 July 1977 and was sworn in as the sixth President of India on 25 July 1977. Reddy worked with three governments, with Prime Ministers Morarji Desai, Charan Singh and Indira Gandhi. Reddy announced, on the eve of India's thirtieth anniversary of Independence, that he would be moving out of the Rashtrapati Bhawan to a smaller accommodation and that he would be taking a 70 percent pay cut in solidarity with India's impoverished masses.