He is under constant monitoring by a team of neurosurgeons and critical care experts at the hospital, an update on his condition issued by the defence ministry said.
It said the former Union minister's vital parameters are stable but he continues to be in coma.
The 76-year-old former defence minister was admitted to the hospital around 11 pm on Thursday after he fell down.
Singh, who had also served as external affairs, defence and finance minister, was expelled from the BJP early this year after he decided to contest the Lok Sabha polls from Barmer in Rajasthan as an Independent after being denied a ticket. He lost the elections.
Image: Former BJP leader Jaswant Singh
Rajnath, Raje betrayed me, cheated me: Jaswant
Expelled BJP leader Jaswant Singh meets Advani
Jaswant Singh:'I don't see the NDA getting the numbers as of today'
Jaswant Singh, the lone warrior
Amit Shah takes charge as BJP chief, lauds PM Modi, party cadres