Veteran actor Sharmila Tagore has revealed that she was battling cancer when filmmaker Karan Johar approached her to play a key role in his movie "Rocky Aur Rani Kii Prem Kahaani".

The cinema icon and her son, actor Saif Ali Khan, appeared in the latest episode of Johar's celebrity chat show "Koffee with Karan".

In the episode, which dropped on Disney+ Hotstar on Thursday, Johar said he wanted Tagore to play the role of Alia Bhatt's grandmother in the movie, which came out in theatres in August.

"I had offered Sharmila ji the part played by Shabana (Azmi) ji in 'Rocky Aur Rani Kii Prem Kahaani'. She was my very first choice. Due to health reasons at that time, she couldn't say yes. But it is a regret I have,” the filmmaker said.

Tagore, 79, said she didn't want to take a risk during the pandemic as she was not vaccinated.

"This is at the height of Covid. They hadn't really grappled with Covid at that time. They didn't know about the vaccine, we were not vaccinated. You know, (it was) after my cancer. So, they didn't want me to take that risk," she said.

Tagore did not reveal the details of her battle and the nature of the disease.

The veteran, known for her roles in Satyajit Ray's “The World of Apu”, “Devi” and Hindi movie such as “Kashmir Ki Kali”, “Aradhana”, “Amar Prem” and “Chupke Chupke”, said not doing Johar's movie is a regret and she hopes to collaborate with the filmmaker in future.

"It will be a regret, and it is something I hope that we can make up for and work together," Tagore said.

Earlier this year, Tagore featured in family drama “Gulmohar”, co-starring Manoj Bajpayee. The film, directed by Rahul V Chittella, was released on streaming service Disney+ Hotstar.