Dear Friend
If it is part of your CTC, the exgratia is to be paid at least once in every year before 30th November on par with bonus payable to the employees of your company whose basic salary is less than Rs 10000/- and who will fall under the purview of payment of bonus act.
Generally, in all new companies where the CTC concept is there, the exgratia instead of bonus is being made as part of CTC to their employees who will not fall under the purview of bonus act. i.e getting more than Rs 10000/- basic salary. In such a case, employer is required to pay exgratia to these employees also on par with employees who will get bonus under the provisions of payment bonus act preferably with November of such year for getting bonus pertaining to previous financial year.
In such a case, why your employer did not pay exgratia to you in every year and why you did not ask them to pay till the lapse two and half year. More over, in some organisations, management will not pay exgraia to retired or resigned employees whose Exgraia is not a part of their CTC. Kindly check it and ask your HR Dept for this. If your CTC consists of Exgratia component, they you are entitle for it and ask your HR dept to pay it or else you can institute a suit in civil court if you are so wish to get the recovery of Exgratia, provided if it was made part of your CTC component
Regards