"Tommy Singh is the scariest character that I have ever played because I don't even drink alcohol, so I don't even know what it likes to be high," the 35-year-old said.
"So, I really have no idea what somebody is going through. I had no idea how I am going to do it. But I felt like it was a challenge that I needed to take up," he added.
"Udta Punjab", directed by Abhishek Chaubey, highlights the issue of rampant drug abuse among youth in Punjab. It features Alia Bhatt as a migrant Bihari labourer, Kareena Kapoor Khan as a doctor who is determined to fight the illegal transportation of drugs, and Punjabi actor-singer Diljit Dosanjh is seen as a police officer.
The film is slated to release on June 17.