If you are interested in studying Computer Science or Coding, then you can take admission in IIIT Surat. In the following several comparisons between these two institutes are listed.
Indian Institute of Information Technology (IIIT)
National Institute of Technology (NIT)
Thus, it can be mentioned that IIITs are the best than NITs, specifically if the students want to establish their career in Electronics and Computer Science. Rather, for other branches, NITs are good, without any doubt.