In his latest release, M.S. Dhoni: The Untold Story, Anupam is seen as Paan Singh Dhoni, father of star cricketer Mahendra Singh Dhoni on whose life the film is based.
Talking about it, Anupam said: "When you are playing an ordinary person, that is the most difficult thing for an actor because there you are not having any typicality as a character - you are just a middle-class man, who we can see in millions on the streets of India."
The 61-year-old says portraying Dhoni's father was "very interesting" for him because Paan Singh Dhoni is an "ordinary person".
"The first thing that I was asked to do was to lose weight as Dhoni's father is little thinner than me. So I lost about 13-14 kg. I did that for a personal reason also as I wanted to lose weight. Then I met him (Paan Singh Dhoni) and felt like he is as simple and ordinary as my own father," Anupam said.
Directed by Neeraj Pandey, M.S. Dhoni: The Untold Story has not just been lauded for Sushant Singh Rajput's performance as Dhoni but also for conveying the story of a commoner's passion for a goal. For Anupam, the film will always be much more than about cricket.
"I don't see MS Dhoni: The Untold Story as a film on cricket. I see it as a film on relationships and an inspirational story. Cricket is just a part in it. It shows how a small town boy goes through all the odds in life and becomes one of the finest cricketers in the world.
"You can say - it's a story of an ordinary father whose son becomes extraordinary. This was the best part for me," he added.
Anupam first came into the limelight with his role in 1984 film Saaransh and went on to star in films like Ram Lakhan, Daddy and 1942: A Love Story. His international credits include Bend It Like Beckham, Bride and Prejudice and Silver Linings Playbook.
His next Hollywood film is The Headhunter's Calling, for which he travelled to the 2016 Toronto International Film Festival last month.
Anupam said the response to the film - directed by Mark Williams - was "amazing".
"While introducing me on stage, my director called me one of the best actors in the world. Whenever I go to a film festival abroad and people say something like that, I feel I am representing my country.
"I was a proud Indian there. The response to the film was also fantastic. My role in it is very good. It was received very well there," said the actor, who is happy with the work Indian artistes are doing abroad.