The actor plays a shopkeeper who loses his faith with God, played by co-producer Akshay Kumar.
He told The Times of India: "It was really sporting of him to agree to feature in a film where a character actor like me played the lead. He believed in the theme.
"I am not being modest when I say I don't see producers putting a 50-crore film on my shoulder. It may happen in the future. One never knows."
The 62-year-old star added that he will be working again with actor-turned-producer Kumar in the future.
"We haven't really decided what Akshay and I will co-produce next. But we'll definitely work together again. He has been a treat to work with. I have my production house Playtime Creations," he said.
"I feel comfortable working with Akshay. As an actor I have to create opportunities of my own. Akshay is a good ally in this endeavour."
It was reported last week that the controversial film will not be released in the United Arab Emirates.
Rawal recently described Ranbir Kapoor as "the future of Bollywood".
Watch the trailer for OMG! Oh My God below: