Is It Legal for Employers to Extend Notice Period and Then Put You on a PIP?

I'm an employee working in Bangalore with a renowned company for 18 months now, wherein I'd resigned in February. In the month of March, my employment had to end with the employer. The employer asked to extend my notice period verbally, to which I agreed as it was the start of the pandemic situation, and they didn't speak about relieving me until July.

In July, they stated that there were performance issues and put me on a Performance Improvement Plan (PIP), intending to terminate my employment without providing any employment benefits. Is this action legal for the employer to take?

Importance of Providing Complete Employment Details

I don't understand why some people fail to provide complete details of their employment when they raise certain contentious issues. It is imperative to mention the capacity of employment, i.e., whether one is a workman, supervisory with a monthly salary exceeding Rs. 10,000, or managerial. This information is crucial for others to assess the situation, anticipate possible consequences, and suggest appropriate remedial measures.