The actor is currently on an eight-city tour to showcase the film, in which he plays superhero G.One.
Khan told New Kerala: "I am extremely exhausted and tired. It is because I am not just promoting the film, I am also doing the post production of Ra.One at the same time.
"Even though I have private planes to travel and five star hotels to stay in but I have been working round the clock.
"The film comes straight from my heart and I believe in it. I have made this film because I wanted to, so why should I be scared of the outcome? In 20 years, you have given me status where I can think of spending money."
The Bollywood veteran has said that he will give up smoking after the film because of his character's mission to wipe out the habit.
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Watch the trailer for Ra.One below: