The Mechatronics branch in itself is not very developed in India irrespective of whichever institute offers it. IIT Patna is a new IIT and lacks the necessary resources and infrastructure while NIT Surathkal has a very challenging curriculum for MTech Mechatronics. The breakdown is 60% Mechanical and 40% Electronics. Students from other domains find it difficult to cope with the rigorous curriculum.
Although the faculty pool comprises good professors, the placement scenario is just average. So try looking for other options or go for IIT Patna instead.