The romantic-drama originally featured Shah Rukh along with a reported cast of Kajol, Rani Mukerji and Ajay Devgn, among others.
"Honestly, I never spoke to him on how I should approach the role. I was aware that Shah Rukh sir and the other star cast was supposed to do the film. At that time, Karan was going to direct it and Mr Yash Johar was producing it," Varun told reporters.
The actor said Karan eventually abandoned the idea to direct the film and did not want to revisit the story after his father's death.
Varun was speaking at the trailer launch of the film here.
Kalank: The trailer of Alia Bhatt & Varun Dhawan’s much-awaited film is finally out! Watch video inside!
"Kalank" is helmed by Abhishek Varman and Varun said the director used to be his roommate during "My Name is Khan" when they both served as assistant directors.
"Abhishek had told me how Karan narrated the story to him. At that time, no one would've imagined that he will direct it someday and I will act in it," the actor said.
Varun, however, said he recently met Shah Rukh after the teaser released.
"He had seen the teaser and I had asked him for his opinion. He had some good things to say about that. He was happy too when I told him I applied 'soorma' (kohl).
Watch the video of Varun Dhawan speaking about Shah Rukh Khan at 'Kalank' Trailer launch event, below:
"He smiled at me and said 'good, you're working hard and doing these roles'. These are roles that will get you closer to the audience'," he said.
"Kalank" is scheduled to release on April 17. PTI