Yes, students of IIT Guwahati MTech Computational Mechanics get placed in both core and non-core companies with decent packages. These students are allowed to sit for almost every core company that visits the IIT Guwahati campus. In Fact, there are many companies that prefer CM students over students from other branches.
The placement percentage is around 60–70% considering placement statistics of the past few years. There are many students who embark on a career in research through Ph.D. in foreign universities. Getting recommendations from IIT Guwahati’s professors will make your OhD easier.
IIT tag will fetch you jobs off campus too, so don’t worry, you will end up with a job either way.