Definitely one of the best movies ever made in bollywood and totally underrated. Way ahead of its time. The story is heavily based on metaphors and every part can be interpreted in more ways than one. Won't give much away but watch it and get your mind boggled and working. Acting and the script was amazing and loved every bit of John Abraham and his acting. He's a an underrated gem for sure.
Now there's this part for which I'll give a 4 rating. Too confusing if you ask me for some audience. Like I have no problem with a thriller and re-watching when I love a movie. There are multiple ways by which you can crack the whole thing; multiple endings. Not easily understandable for everyone. Which can make you leave it halfway or even abandon the movie. Or if you're passionate enough, make you watch a multiple times to get it wholly. This is not a drawback just an opinion which makes me mention it.