I never was a Srijit Mukherji fanboy, and this movie most certainly didn't change my mind. Everything in the movie is wrong, I don't even know where to begin my review. Well, let's start with the characterization.
Santu in the books doesn't talk much (unlike his friend Jojo), but underneath his quiet demeanor, he is extremely street smart, indomitable and courageous. Santu in this movie is like a scared, wet rat, fleeing at the onset of anything resembling danger.
Kakababu in the books isn't a boastful person, in fact, he dislikes being praised even by others (like Narendra Verma, a frequent associate). Kakababu in this movie is full of hyperbole and bravado. "Go back and tell people Sherpas can have the last name Roy Chowdhury", are you serious?
There's also a woman who is supposed to an officer in the Indian army (a character not present in the book but obviously the director wanted a female in the otherwise all male cast in order to lure a certain demographic of viewers), and is played by a Bengali actor who tries really hard to sound like a non Bengali. What's up with the fake accent lady?
Then there're these unnecessary and annoying songs that seem to be written to please Shah Jahan, praising the king and all.
Watch commercials on the TV instead of watching this movie, it'll be a far better use of your time.