The movie reportedly centres around ten evils in the world, one of which is smoking.
Khan told DNA India: "I want to give up smoking and will soon do it. Even my daughter keeps on asking me when I will quit it. I will give up the habit after Ra.One releases.
"There is one scene in Ra.One which speaks about the ill-effects of cigarettes,which is in the form of conversation between father and son."
Khan said this week that he made the film because he had never chosen a project specifically for his children before.
He said: "I have come a long way and tasted success as an actor, but my kids would keep saying that I don't make films for them. So I decided to do something different for cinema itself and that's how Ra.One happened."
However, Khan admitted in September that he wants to star in a "sweet, romantic film" as he is tired of appearing in action movies.
Watch the trailer for Ra:One below: