Firstly it's your decision where you want to put yourself. It might be difficult for you to choose. So let me make it a bit easier for you. Both are good in their own aspects. If you want a to join a non-core field then choose JSS but if you really what to learn all about engineering and know what exactly is so you should go fir mmmut. And trust mmmut is the best according to me. The faculty, education system is very good. At the end of the day it's you who should make a choice, so make it worth. 

Good look. 

Hope this helped you!