Hi Vishal,

You can change your branch after first year, but only if you score very high GPA(Grades). A few students are able to do it, but for most of them, it is nothing but a trap. Initially everyone is confident that they'll get their branches changed, But all IITs have a rule that only 10% of the students from each branch can change their branches, and the branch's strength they are going into, should not increase beyond 15% of its initial strength, IIT BHU might have somewhat different rule, but all IITs follow this more or less. You are advised, to go to the institute's website, and see the branch change rules, before taking a decision.

Hope it helps.