Sources claim that Shahrukh Khan and director Anubhav Sinha were planning to have more drama with fun and action elements in Ra.One. They were impressed with Sanju's dedication and the way he buffed up his body for Agneepath. So they decided to get the actor on board.
Sources further say that Shahrukh and Anubhav approached Sanju and requested him to do a cameo in the movie Ra.One. Although he was interested to act in the action flick, he had dates' issue as he was busy with Karan Johar's next project Agneepath. But Karan is a close friend of Shahrukh and he graciously gave a few of Dutt"s dates for Ra.One.
However, Sanjay Dutt and Priyanka Chopra are not appearing in any romantic or dance scene, but they star in a stylised action sequence of the movie Ra.One. Sources claim that initially, the two of them were to shoot for just a day, but now they have extended it by a couple of days as SRK and Anubhav want Sanju to do some great action scenes.