"We have no proof that he flew the first plane. We do not know if it was true or not but we should know that someone like him existed. The film is about a conspiracy theory," Khurrana told reporters here.
He is playing Talpade in 'Hawaizaada' which releases on January 30.
Directed by Vibhu Virender Puri, it is an inspiring story of the maverick Indian scientist-engineer who is believed by some people to have built and flown the world's first unmanned aircraft, eight years before the Wright Brothers in 1895.
"We were told that he flew the plane in Mumbai's Chowpatty in 1895. Hundreds of people including Bal Gangadhar Tilak were present that time. He could not get it patented as India was then a British colony. The media was controlled by the Britishers and so there were no reports. How come all inventions are made by the West?," Khurrana, 30, said.
He said very little is known about the life and personality of Talpade.
"It is very difficult to make a film on him. It is very easy to make a film on Gandhi, Mary Kom and Milkha Singh because we all know them. Here we don't know much about him," he said.
The actor who has made his mark in films like 'Vicky Donor' and 'Nautanki Saala' said he has been playing the conventional urban guy in his recent films.
"But now this is a change for me as I am playing a Marathi guy of 1895. The body language is very different. Even the language is in its purer form as he (Talpade) speaks Marathi, Hindi and Urdu," Khurrana said.
The actor has also given his voice to Mirza Ghalib's ghazal 'Dil-e-Nadan' in the film.
"I have lost the fear of heights as I was suspended 40-50 feet in air for sometime. And we had to take 20 takes of those gliding shots. Its not with a body double," Khurrana said.
It was his mentor and 'Madras Cafe' director Shoojit Sircar who advised him to select the unconventional script.