If you have the advantage of home-state quota then in order to get Computer Science in NIT silchar you should have a Gen-EWS rank of at least 5200 but in case you wish to be sure that you will get it in the eariler rounds then you should have a gen-ews rank of around 4000. At this rank you should be able to get NIT Silchar in the earlier rounds of counselling. Hope this helps.