Biopics are a rare genre in Bollywood and Mehra knew what he was letting himself into by making a film on one of the living legends of sports.
The director started with producing the film on his own but had to let go of 50 per cent of its rights to complete the film, which starred Farhan Akhtar as Milkha Singh.
"Raising money was a challenging task but we always believed that we were going to make it. For three years, I knocked at every door but nobody picked it up and they are all friends," Mehra told PTI in an interview.
Bollywood seems to be waking up to the magic of biopics recently. Sanjay Leela Bhansali is making a film on boxing champion Mary Kom with Priyanka Chopra, there are reports of a biopic on Hockey legend Dhyanchand while Anurag Basu has already announced plans for a film on Kishore Kumar.
"It is still very difficult to make a non-formula film without producing it. I hope it opens a trend where we don't have to follow a formula for a film to be successful. In Bollywood, your project becomes economically viable only when you pick up a star, otherwise nobody will entertain you," Mehra said.