The 71-year-old Bachchan was to play the role of a Pakistani lawyer in the biopic.
"We did approach him, but after reading the script, he informed us that he was playing a lawyer's role in another film that he had already committed to. We mutually agreed not to cast him in this film, though I would have loved to have worked with a legend like him," Ghai said in a statement.
The makers are still looking for someone to fill the role.
"We are still talking to other actors for this role and will soon be announcing the name," he said.
Directed by Ishwar Singh, the film features Anurag Sinha and Sonakshi Sinha.
--IANS (Posted on 17-12-2013)