My brother is pursuing MTech Mechatronics from IIT Patna. So, I have some ideas about the degree program. If you are a Robotics or Mechatronics enthusiast, you are perfect for this course. 

• The course curriculum is great. It is easy to score decent CGPA as compared to other departments.
• There are two departmental labs. One of the labs has necessary instrumentation, to carry out the course work. The other is set up by Bosch to study engine ECUs.
• Placement for this branch is average. If you are talented and work for it you can also get internship offers.
• Companies like TVS, Tata Innovation Lab visit the campus for R&D profiles.

MTech Mechatronics at IIT Patna is a decent option, you can definitely go for it.