Kangana is preparing for her next movie and that is "Once Upon A Time in Mumbai" with Ajay Devgan, Emraan Hashmi and Prachi Desai and the film is directed by Milan Luthria. According to reports, Milan considered Katrina Kaif earlier, but wanted to get the right person so he waited. Then he was so impressed by her act in "Fashion" and she is now casted in the film and will be playing Madhubala according to reports while Ajay Devgan play Haji Mastan.