Full & Final settlement - Variable pay missed - legal approach?

I worked in HCL Technologies from 10-Mar-2011 To 05-Sep-2017.
HCL has one yearly salary component on its salary structure that is YEPB (Year earned performance bonus) which is 10% of CTC which will be paid out on fulfilling below criteria every year.
* Should serve in the entire appraisal cycle (01-Jul To 30-Jun)
* Should be part of Aug payroll
* Appraisal rating "Met expectation"
Even though I met all the above criteria I have not paid with the YEPB in F&F. I dropped email to HR and my previous manager but no response.
Could you please advise I can legally approach

I have same experience, I worked in HCL for 2.5 years, the variable i got for 2nd year completion got deducted in F&F, which is not clarified by anyone yet ,

The criteria, should serve in the entire appraisal cycle (01-Jul To 30-Jun) & should be a part of Aug payroll are factual and verifiable, much would depend on the appraisal rating of having "Met expectation". Do you have an open system of performance appraisal and what is the performance feedback you have?. Met expectation or not, is it based on KPIs and what is your score?. Is there a bell curve method used to assess relative performance? The details of the Policy in this regard holds the key. You can bring out more details of the Year earned performance bonus scheme.

I have same experience, I worked in HCL for 2.3 years, the variable i got for 2nd year completion got deducted in F&F