To become an assistant professor at IIT Ropar you must first obtain a PhD. This is the minimum eligibility criteria for any IIT to apply for the post of assistant professor. 

Then you will have to compete with many other candidates and to stay above the competition you will need to have an outstanding academic career throughout. 

You will also need to have various published papers in many international and reputed journals. This will give you an edge over others.

This is a suggestion beyond the scope of this question. But if you can start low in a company and struggle for 2-3 years, I believe that you can land a more lucrative and satisfying job later on. Doing an M.Tech and then a Ph.D. will take a very long time.