Yeah, I suppose you can obviously do that ,provided you perform excellently in JEE Main.Only thing which you cant do is reappear for JEE Advanced and move to another IIT.

But my suggestion would instead of planning to waste a year and work for JEE again after moving to IIT, which itself is quite difficult and is quite a tedious and monotonous, you could plan to work seriously with the curriculum in first year, and subsequently slide branches to CSE/ECE/EE and hence open a whole range of opportunities to yourself.

At IIT BHU, the Branch Change policies are comparatively relaxed and easier than its older couterparts, IIT Kanpur, IIT Kharagpur and other top IITs.

One thing you can rely on in IIT BHU, is the sea of opportunities you get during Internships and Placements be it in Core/NonCore/Finance/IT/Consultancy besides the IIT tag. So, the ball's in your court, choose wisely, at the end its your career.

For more information on college prediction do follow the link below

https://engineering.careers360.com/jee-advanced-college-predictor?icn=QnA&ici=qna_answer