The reason behind the rift seems to be Shahrukh choosing Arjun over Riteish to play the villain in Ra 1 in spite of Riteish being the first choice. According to sources, Riteish was chosen for the negative role. Even director Anubhav Sinha wanted Riteish to do the role as he had already worked with the actor before in Cash. Riteish was finalized for the project and his remuneration had also been fixed. However, Riteish then read in the newspapers that Arjun had been chosen as the villain in Ra 1.
Arjun was unsure about playing the role as he was suffering from a back problem. He was chosen later though. And while Riteish is upset about his ouster, he hasn"t spoken a word about it to SRK. He mentioned it to a few close friends but he feels Shah Rukh or Anubhav should have informed him that he would no longer be doing the film.
Shahrukh will be playing a super-hero like character in Ra 1 and Arjun will be the villain. The movie began rolling earlier this month. Kareena Kapoor plays the heroine. The movie is based on gaming and super heroes.
However, now Riteish states that he was never offered the film in the first place.