Interview process is little bit tough, all depends upon department for which you are applying. Questions are based on core concepts as well as practical based concepts. Internship and project also get counted.

Cfd related questions ,Turbulence modelling, Multiphase modelling, heat transfer, Fluid mechanics, Meshing ( structured and unstructured), Discretization schemes(PISO, SIMPLE, SIMPLEC, COUPLED), About the intenships and certifications, Basic Mechanical Engineering questions