If we are talking about which is better SIT or NIT then NIT is far better than SIT. NIT requires good score in JEE whereas SIT as it's own entrance exam . If we miss JEE score we can opt for SIT. SIT also has good infrastructure, facilities ,etc. If we compare both  NITs are government institutes and are tougher to get admission and it has different syllabus than private colleges. If I had to choose between the two ,I will choose NIT.