"I have not signed any film yet. I have just begun to read scripts and explore the possibility," Aamir told reporters here at an event when asked whether he will do Rakesh Sharma biopic or not.
Gossip mills are abuzz that the 51-year-old actor will be seen in the biopic on Sharma.
The "Lagaan" star feels it is unfair to talk about a film that he is yet to sign.
When prodded further whether script of Rakesh Sharma biopic is the one film that he is reading, Aamir said, "It is not fair to talk about a film till I sign it. There are lot of people who approach me and they do it with confidence.
"When someone narrates me the script I don't tell anyone about it. And if I don't do it (film), then it is said Aamir rejected the film and why he did and all these things come up," he added.
The 'Ghulam' actor feels people approach him with faith and he likes to uphold that.
"When people (director) come to me they come with faith and I like to uphold that. Whichever script I hear one will never come to know about it. So, I will neither confirm nor deny your question," he added.
Rakesh Sharma is a former Indian Air Force pilot who flew aboard Soyuz T-11, launched in April 1984, as part of the Intercosmos programme.
Sharma was the first Indian to travel in space.