'Kalki 2898 AD' director Nag Ashwin has revealed how he managed to get filmmakers SS Rajamouli and Ram Gopal Varma to make special appearances in the film. "I had to convince them and they were gracious enough to come on board to support the film," Ashwin stated. He further said that Amitabh Bachchan was his only choice for Ashwatthama's role.