As per the analyzing report of Careers360 NIT Patna has AAA+ rating which means good & NIT Jamshedpur has AAAA rating which means very good. For Mechanical Engineering NIT Jamshedpur is the best option. The rating is also based on the reserch of the college based on the placement, faculty & Industry Exposure etc. You can also check the placement of the colleges with the given below links.

http://www.nitjsr.ac.in/tap/portfolio/

http://www.nitp.ac.in/php/placement_home.php?pp=home

You can also check the genuine reviews of the college with the given below links.

https://engineering.careers360.com/colleges/national-institute-of-technology-patna

https://engineering.careers360.com/colleges/national-institute-of-technology-jamshedpur

Good Luck!