Sorry to say but you haven't scored enough to get the cse as CSE is known to be the core branch of engineering hence it's cut offs are high as compared to other branches so either try next year with more preparation and score more to get CSE or you need to compromise with your choice of branch but I would suggest you if CSE is your main focus then you should try in some other college there are number of private colleges and universities in which getting CSE isn't that difficult Also there's a fact that gitam conduct its own enterence exam GITAM GAT so very less portion of seats are reserved for jee main candidated this also increase the competition. 

Good Luck!!