Which one to choose, CSE at IIIT Raipur or metallurgy at NIT Raipur?

Metallurgy at NIT Raipur is a much better option than CSE at IIIT Raipur. The reason for this being, NIT Raipur is a well-established institution so you will have better chances of getting placed than in IIIT Raipur, no matter which branch you opt for.

According to the recent placement highlights, the average package offered at IIIT Raipur was INR 7.50 LPA whereas, at NIT Raipur, it was INR 9.5 LPA.

NIT Raipur provides a sliding option, too. So, even if you are not getting CSE in the first place, you can easily change from whichever branch you are into CSE within two years.