I am working in mnc Backoffice centre.
i have come across a case where an employee who was terminated for going on unapproved leaves has returned after 2 years and the employee says that he is willing to pay the dues outstanding to get the relieving and experience certificate.

If yes then also help me how to calculate the dues. (on which basis)
At the time of his termination the notice period was 3 months and presently it is 1 month.

Pls give me your valued feedback.