Similar to other branches mechanical engineering also consist of aptitude round, Group discussion round and HR round. These are common, so the questions may not vary huge.

       But when considering Technical Round, the questions may vary for each fields. Some of the subjects that you should focus are Fluid Mechanics and Fluid Machines which are  very important part of your syllabus. And there is maximum chance of getting questions from this subjects.

       Prepare subjects that are related to the company to which you are going to attend the interview. For example, Material Science & Engineering is an important topic for companies in the field of steel making, casting, etc. If you are appearing for an interview related to the company that deals like Heating, Ventilation, and Air Conditioning e.g. VOLTAS, Carrier, HITACHI, you need to be good at Heat & Mass Transfer. Similarly for companies like John Deere, CAT, JCB you need to be good at Fluid Power and Control