 Dilip Prabhavalkar , who portrays Gandhi , read Gandhi 's works " once again " to prepare for his role . Boman Irani prepared for the role of Lucky Singh by spending time with <unk> ( male Sikhs ) in auto spare parts shops to research his role . Vidya Balan ( " Jahnavi " ) met with a couple of radio jockeys and watched them at work . 
