Employer terminated me immediately after I returned from medical leave, is this legal?

I work for a company in Bengaluru and was on a medical leave for a surgery. I returned to work last week and was suddenly terminated without any prior notice or valid reason. This has left me extremely anxious as I relied on this job for my medical expenses. I suspect they considered my leave a burden. Do I have any legal standing to challenge this termination under Indian employment laws? What should be my next steps?