Generally in the interview they do not do in depth theory but all they check is your concepts and foundations.
Interviewers also look for what you have done practically, preferably pro actively. The college project will help if you have actually done it with your own hands. It can be time spent in the industry as trainee or intern.
Focus on queries related to design, safety and maintenance.
To an extent, preparing for GATE also helps in cracking technical interview.

Book for reference: Objective Mechanical Engineering and Technical Interview: Mechanical Engineering Objective Questions with Answers + Technical Interview

The above shall help you with your purpose.
Good luck!