In recalling his history, Belram thinks about his murder of Mr. Ashok, who was his master at the time. Belram had been forced to become a driver because of poverty, and while he appreciated the work that Ashok gave to him, he was also resentful of his social class and wanted to be free. As the novel progresses, the corruption of government and law enforcement grows stronger, and Belram realizes that he cannot get ahead without becoming corrupted himself. He does not rationalize it beyond that, however, and does not lie to himself about the evil of his deed. To escape the crimes of Ashok and his father, Stork, Belram kills Ashok, robs him, and starts his own business.
Kill enough people and they will put up bronze statures to you near Parliament House in Helhi -- but that is glory, and not what I am after. All I wanted was the chance to be a man -- and for that, one murder was enough.
(Adiga, The White Tiger, Google Books)
His reason for the killing was to escape the crimes of the area, but at the end of the novel he discovers that he is responsible for many of the same crimes as the people he has fled; also, it is likely that his family was killed in revenge. Belram accepts this as a given, and decides that the extra deaths he has caused are acceptable since he has won his freedom, and now no man is his master.