In the film, directed by Ashwini Iyer Tiwari, the 27-year-old actress is playing the mother of a 15-year-old girl.
"When the casting director Mukesh Chhabra came with this idea of a mother-daughter film, I thought I had to play the role of a daughter. I was shocked and told him that my career will go down as it's a mother's role," Swara told reporters here at the launch of the trailer of 'Nil Battey Sannata'.
"I had played Salman Khan's sister (in 'Prem Ratan Dhan Payo') and then I get to play a mother (in Nil...) soon I might even get offer for the role of a grandmother," she said in a lighter vein.
Swara said that actresses typically play roles suitable to their age or roles of younger people.
"There were people who told me it's not a good idea to do this role. I was scared about my image," the actress said, adding that when she read the story of the film she fell in love with the idea.
"I thought I will just read the script as the casting director is a friend and say that I did not like the story. But rather I loved it (story)," she said.
Swara said she was told by the director to gain weight for the role.
"I was asked to gain 10 kg. So I kept eating and eating. But midway through the shoot, she (Ashwini Iyer Tiwari) told me to lose some weight as I was looking a bit too healthy. It is difficult to lose weight," she said.
Swara considers walking the red carpet is like appearing for examination.
Considering that she has worked with fashionista Sonam
Kapoor in "Ranjhaana" and "Prem Ratan Dhan Payo", Swara said she talked girly stuff with her.
Swara, however, said that actors are remembered for the work they do.
"It was great experience of working with her (Ratna Pathak Shah). She is brilliant and an outstanding actress," Swara said.