Hi nitesh ,
I regret to inform you that with a rank of 7786 under any sub category its difficult for you to get admission into any prestigious college of engineering like nits or iiits with computer science branch.
As computer science branch is one of the core branches so it has high cutoffs for the candidates to get admission.
Either you take admission into any other branch in some reputed nits or take admission into any other college with your desired branch.

Hope it helps!!!