Dear Madhab
Normally you will find following wordings in appointment letter under notice period / termination / separation clause “you will have the option to terminate the contract of employment by giving 1 month notice in writing, or payment of the basic salary in lieu of notice period to the Company. Similarly, the Company may also terminate the contract of employment, without assigning any reason, by giving 1 month notice in writing, or payment of the basic salary in lieu of the same”
The way you have choice of separation through resignation letter similar way company have choice of termination with or without giving any reason.
Resignation is always better than the termination. In case of termination getting 2nd job becomes difficult, in case of resignation still companies are considering CV’s.
It is difficult to prove in court of law “forceful Resignation”,
If still you wish to process further, you can contact lawyer, they will give all ways to fight for your case, now you have to decide by giving full stop here and go ahead next step for career or file legal case.