First of all there is no consumers court involved in Employer employee relationship. Besides this the variable part is the very common practice and is paid only if the employee is in service at end of 1 year of joining or package appraisal.
First of all do not accept your FNF .
Write to the top person of the organization, pointing that you left the organization at their instance and against your will because of lack of projects and you were put on bench. There fore you are entitled to the variant pay and your FNF must include it.
You also point out that your Colleague who was asked to leave before 15 the Dec ,was paid variable pay. They cannot mend the rule in unjust manner.
If it does not get settled at that level then appropriate Authority will be Labour Commissioner to lodge your complaint and Consumer Court will not have jurisdiction to handle your matter.