"He was alert mentally till the very end," Rahul said.
"He passed away very peacefully, led a very full life," he added.
Born in Hadali, now in Pakistan, he had, among others, served as the editor of The Illustrated Weekly of India, where his column, "With malice towards one and all", flagged with the bulb symbol with his caricature inside, made him an iconic figure. He was also editor of The Hindustan Times and National Herald.
Known for his colourful writings, sharp sense of humour and love for the good life, his writings weren't just limited to novels and short stories, Khushwant Singh oeuvre ranged from political commentary to contemporary satire.
"He was a gentle person and a great admirer of Mahatma Gandhi and Mother Teresa. He believed in good thought and good deed. He hated hypocrisy and fundamentalism," Rahul said.
He was also a member of the Rajya Sabha from 1980 to 1986.
Vice President M Hamid Ansari, in a tribute, said: "Khushwant Singh had a long, prolific and illustrious literary career spanning several decades during which he wrote on subjects varying from politics to poetry to issues of social concern.
"He was particularly admired for being fearless in expressing his views in his writing and speech."
