Rishi initially said no. Arshad Warsi was being considered for Dawood's role. But Advani had his heart set on Rishi Kapoor. And he finally got him.
After Saif Ali Khan in Agent Vinod and Salman Khan in Ek Tha Tiger, it's Arjun Rampal who plays a RAW agent in D Day. Arjun is mighty kicked by the prospect of working with Rishi Kapoor.
D Day is about RAW agents, played by Arjun Rampal and Irrfan Khan who are assigned to bring Dawood back from Pakistan by road. Since permission to shoot in Pakistan is impossible Nikhil Advani would be shooting the Pakistani scenes in the Kutch district of Gujarat.