NIT Puducherry has recently shifted to its permanent campus, although IIITDM’s campus seems better. As for the faculty, again IIITDM has an upper hand but you will have to figure out an approach towards them. 

Both the institutes have a fairly comprehensive and challenging curriculum for their students. They are both good placement wise but if you have more than 7.5 CGPA you will be allowed to sit for all the companies in IIITDM. You can see which suits best to your requirements.