Employee Self Resignation after PIP review of unachievable goals - eligible to at least get salary in lieu of notice?

Hello Leader HRs, I am facing a situation wherein I am forced to put down papers after PIP review of unachievable goals.
I have a 3 months notice period clause in my LoA .
Just want to take your feedback, if I am eligible to atleast get salary in lieu of notice.
Just want to understand if I am legally right or wrong. PIP reasons and all , I know was just a mean to get rid of employee.

Let us start from the process flow mapped to PIP for your understanding.
Performance Improvement Plan (PIP)
Formal method of correcting behavior/performance and encouraging employee’s success. If your performance is below average.- The Manager needs to develop a performance improvement plan, in agreement to your views.
In case the Manager has changed:
the previous manager and new manager to jointly develop PIP.
the previous manager to give support in developing the PIP in consultation with new manager and new manager to track the PIP. PIP period must be specified time period – 3 months is suggested normally. This timeframe is provided for you to shape-up. if there are no improvement, then as per the clause of your appointment letter and PMR policy, you will be informed to resign amicably. the salary will be provided as this is a resignation case.
This is not a forced separation, but as per the workflow you were informed well ahead of the consequences.
You should have all the documents of PIP, the action plan and the final comments. Dont be tense, the company has given you timeframe to improve. Look out of new opputunities and learn the areas of improvement.
Thanks
Neena Reddy

Thanks for your inputs Neena.

The thing is this case is more of a commercial issue. Since, I am a high paid employee, they framed such a PIP which was unattainable. I discussed with my line manager too many times about that, but he always replied it's his manager's call and cann't modify it.

When I used to reach out to HR about the Targets and other biasness thing happening, he also was helpless. I thought PIP review might be one time wherein I could highlight my concerns and I did that. But I could sense helplessness from their response as well.

They also agreed to my areas of concern in then call, but to my wonder, I received call from my HR to resign.

Today, I have finally resigned and was eager to know if salary of the notice period be given to me as this COVID has actually frightened me.

Appreciate your time and thoughts.

The poster seems to have agreed to the PIP despite knowing well that the standards set were unattainable. Only in order to avoid the stigma of termination by the employer, he would have resigned. Therefore, as per the notice clause, he has to serve the notice period or pay in lieu thereof. If the employer accepts his resignation with immediate effect, it implies that the notice is waived by the employer.
If he feels that he was actually coerced to put down the papers and the PIP is a handy tool to make believe that he is not suitable to the job and as such it amounts to constructive dismissal, he can fight it appropriately.
As it is, therefore, in my opinion he is not entitled to any notice salary.