The actress is playing Smitha in Ekta Kapoor's upcoming Dirty Picture.
Since she has taken on the part, the star has reportedly been encouraged to put on weight to resemble the tragic Bollywood icon.
According to Mumbai Mirror, Balan will have to wear the cosmetic enhancers as production begins on May 30th.
She was recently told by director Milan Luthria that she needs to become more "comfortable" with her body for the role, as Smith was known for her easy on-screen sensuality.
Balan had confessed after signing up that she has reservations about playing Smitha, who died in September 1996 at the age of 35 after failing to become a producer.
Kapoor has said that she expects "unbelievable critical acclaim" for the picture and has also predicted that Balan will receive an award for her portrayal of Smitha.
