Saswata Chatterjee declined to reprise his role as Bob Biswas as he did not want to play the character anymore, Abhishek Bachchan was then approached for the role and signed.
In the movie Bob is seen using a Motorola Razr phone. In real life Abhishek Bachchan, who is playing role of Bob Biswas, has been endorsing Motorola brand in India since 2007.
A standalone story to the private contract killer Bob biswas from Sujoy ghosh's Kahaani starring Vidya balan. The role of Bob biswas earlier played by Saswata is now being played by Abhishek bachchan and the movie will focus mostly on the story of Bob and his life as an paid killer
Abhishek Bachchan's fifth film under Red Chilles Entertainment, he previously appeared in Om Shanti Om (2007) & Happy New Year (2014) while the film rights to Yuva (2004) and Guru (2007) were purchased by the company.
There is a common misconception that Saswata Chatterjee was replaced outright by Abhishek Bachchan, but this turned out to be false as Saswata turned down the role as he did not want to play the character anymore, having moved on from it considering it had been 9 years since Kahaani (2012) was released.