The industry legend was last seen in the 1997 Bollywood hit Judaai with Anil Kapoor.
She told The Times of India: "If had got this movie five or ten years ago, I would have done it. I felt as woman, wife, mother, I could relate to the character, I liked its simplicity and the subject of the film.
"I wouldn't have had this comeback if this script had not come to me. It all just happened. It is a good thing that the film is coming at this good time when people like to see something different."
She added: "My husband wanted to produce a film for me. I heard the subject but nothing excited me where I could leave my children, house and family and be there in the studios."
Co-star Amitabh Bachchan recently praised the actress for her moving performance in the film.
In May, she denied that returning to the film industry will change her priorities as a mother and wife.