Section 6(2)(iii) in Tamil Nadu Revised Pay Rules, 2017
(iii)in the case of a person whose services were terminated on or after 1st January, 2016 and is consequently unable to exercise the option within the prescribed time limit on account of discharge on the expiry of the sanctioned posts, resignation, dismissal or discharge on disciplinary grounds, the option shall be exercised within three months of returning to duty or reappointment to the post.