The Desi Boyz actor has his own production house which has released international films such as Breakaway.
Kumar told The Times of India: "Acting is way easier than production. Acting means you're just handling yourself; in production, you are handling a unit of 300 people.
"It's tough. You're handling other actors, which is a big job. You have to ensure the film's success. There are lots of things.
"I don't hurt [actors], but I say it in a very diplomatic way - I'd say [there are] date problems and all."
Kumar's next project Oh My God sees him playing both a Muslim and a Hindu.
In March, the actor admitted that 2011 was an unsuccessful year for him and that he plans to concentrate on action films