Navigating Job Offers: How to Handle Multiple Interviews and Avoid Premature Commitments

I am expecting both companies to offer me the job. How do I avoid signing a contract with a company I met earlier?

I do not know the present practice in India. Normally, people make an oral offer at the time of the interview and then send a written offer stipulating the pay and conditions, etc. You can always ask for time to consider the offer before deciding, just as organizations take time to decide. You do not have to tell either of the companies about the interviews. Maybe other HR experts will have a different view.