The 47-year-old actor, best remembered as Sunny Deol's bum-chum in 'Gadar', died Monday morning.
Vivek, who had also acted in many Punjabi films and Jaspal Bhatti's shows like 'Flop Show', leaves behind a wife and three children.
'His daughters are teenagers and his son is even younger. It's such a sad thing to happen to a man who always made everyone laugh,' said Raj Babbar's son Arya Babbar, who had worked closely with Vivek.
The Deol family, busy promoting their latest film 'Yamla Pagla Deewana', was plunged into mourning when news came in of the death of Vivek who featured in several films with them came in.
Bobby Deol, who has acted with Vivek, was too distraught to speak.
Sunny, who worked with Vivek in 'Maa Tujhe Salaam', 'Indian', 'Champion' and 'Gadar', said: 'This has come as a complete shock out of nowhere.'
'We were so looking forward to the release of our film 'Yamla Pagla Deewana'. This tragedy has clouded our excitement completely,' he said.
Said Arya Babbar: 'He died of a heart attack all of a sudden. I met him about 20 days ago when he had come to see my mother's (Nadira Babbar) show. He was absolutely fine.'
'Vivek was with me in my debut film as well as in our other home production 'Kaash Aap Hamare Hote' which launched my sister Juhi,' he added.