A few years back, my brother applied for the MS program in Engineering Mechanics at JNCASR. The written test was conceptual. They aim to test your mathematical skills and fluid mechanics knowledge. Solving the Mathematics portion can be easy if you know the proof of all concepts. There were also questions regarding Heat Transfer. 

The Interview will depend on what you have written in the test. They may ask to prove what you have written in the paper. They will ask you to choose a topic of your choice and ask questions about it. They will ask you about your B.Tech project.