Jawaharlal Nehru was Prime Minister from 1947-64. He was a widower. Kamala Nehru died in 1936.
Indira Gandhi was PM from 1966-77 and 1980-84. She was a widow. Feroze Gandhi died in 1960.
PV Narasimha Rao was PM from 1991-96. He was a widower. His wife Satyamma died in 1970.
AB Vajpayee* was PM from 1996-96 and 1998-2004. He was a bachelor.
Sonia was Super PM from 2004-14. She is a widow. Rajiv Gandhi died in 1991.
Narendra Modi is a bachelor/single, depending on how you look at it because he was a victim of an illegal child marriage which did not go forward.
That covers about 65/77 years of India’s Independence.
*The run up to 2004 was interesting because Vajpayee was PM, bachelor APJ Abdul Kalam was President and Sonia was Leader of the Opposition.