I read the book years ago and quite liked it. The movie stays true to the book. The setting of the story is the 2000s when the BRIC boom was in vogue, and the idea that the brown-man and yellow-man were going to snatch world leadership from the white man looked plausible.
Performance wise Balram was outstanding. Rajkumar Rao played the role of a rich Indian with an American stint and an Indian-American wife Priyanka Chopra. I have seen better performances from Rajkumar Rao. Priyanka Chopra's performance was fine.
The story of a poor Indian boy in trying circumstances and coming out triumphant has been explored in numerous engaging movies like Slumdog Millionaire, Life of Pi, Lion. Its a good watch