Police said the accident occurred this evening when a speeding bus of Rajasthan Roadways broke the road divider and rammed a car in which the family was travelling and was near the NSG camp.
The deceased have been identified as Dinesh (28), his wife Saroj (25), their minor daughter and a close relative, Investigating officer Manjeet Singh told PTI.
They were going to Khatushayam temple in Rajasthan.
They were taken to a hospital where they were declared brought dead by doctors, Singh said.