My employer terminated me without notice after 5 years of service

I've been working with a tech company in Bengaluru for 5 years. Last week, I was suddenly terminated without any prior notice or warning. I'm shocked and financially stressed, as I had no time to prepare or search for another job. They claimed 'performance issues', but I have no written warnings or evaluations indicating problems. I believe this is unfair and possibly illegal. What should I do to challenge this termination and seek compensation? Is there a specific process to follow under Indian labor laws?