The upcoming biographical sports drama features Aamir, 51, as Mahavir Singh Phogat, who taught wrestling to his daughters Geeta Phogat and Babita Kumari. The trailer of the film was released yesterday.
Chopra, who produced Aamir-starrer "PK" and "3 Idiots", was applauded the actor for his efforts.
"I really like Aamir as an artiste. He is excelling himself," Chopra told reporters on being asked how he found the trailer.
The filmmaker, who attended the 18th Jio MAMI Mumbai International Film Festival with the superstar, was asked if Aamir was setting a trend in an industry where often actors hesitate to play characters older to their age.
To this, Chopra said, "Aamir is a mad man. We call him 'idiot' like you saw in '3 Idiots'. So, only he can do this. If you aren't that then you can make a lot of money and leave the world but 'idiots' (people crazy for their work) remain forever.