I am assuming you wish to study B.Tech CSE/IT from either of the two.
IT at NIT Raipur is a good branch with a good placement record. However, its faculty and curriculum are not up to the mark. The placements are better in CSE as compared to IT.
On the other hand, IIIT Naya Raipur is a new college. So its alumni base is yet to develop. But it has a good placement record for CSE. The median salary ( for B.Tech and M.Tech CSE) stood at INR 15 LPA during 2022 placement season. The Infrastructure of IIIT Naya Raipur is much better. It is newly built and modern. Also, its curriculum contains the latest topics, and is in line with the syllabus of top IIITs.
Thus, IIIT Naya Raipur is a good choice for B.Tech CSE. But you can also choose IT/CSE at NIT Raipur.