The tragedy struck while Nischol and his close friend actor-filmmaker Randhir Kapoor were on their way to Pune. The two had left at around 10.30 am.
"However, even before they reached Sion in central Mumbai, Nischol suffered a massive heart attack. He was rushed to a nearby hospital where he was declared dead," sources said.
The mortal remains of Nischol have been brought to his residence in suburban Khar and the funeral is scheduled to take place at Santacruz crematorium in the evening, they said.
A product of the FTII, Nischol made a successful debut with `Sawan Bhadon` in 1970 and went on to star in several films like `Victoria No 203`, `Dhund`, `Chhalia`, `Parwana`, `Buddha Mil Gaya`, and later as character actor in `Major Saab`, `The Burning Train` aming others.
In the early 90s, he had made a successful transition to the small screen with the popular sitcom `Dekh Bhai Dekh` alongside Farida Jalal, Shekhar Suman. The show was produced by Jaya Bachchan.
He was last seen in films like `Khosla ka Ghosla` (2006) and Break ke Baad (2010).
His wife had committed suicide in 2006.