Rejoin In PSU Bank After Resignation

I resigned after servicing 8 years (joined as a clerk, promoted to officer) from a PSU bank before a merger of the bank in Augst, 2019 due to personal ground & now the bank has been merged to another PSU bank in 2020. After that, I started for competitive exams but recent Covid-19 breakout has made me doubtful about my future prospect as my present age is 34 years and to date, there is no hope for pending exams to begin and so now I wish to return to my previous workplace. During the period when I was in service I had served a notice to the bank for Immediate resign and did not serve any notice for 90 days but continued to attend office till my resignation was accepted after 2mnths. My bank had a rule that anyone who wishes to resign with immediate effect has to pay a 3 months salary but in my case despite serving immediate resign notice and serving more dan 2months after noticing I had to pay 90 days salary & no adjustment was done. Ds that mean labour law violation. In any case, is there any chance to Rejoin even as a clerk.