Notice Period not served due to mental harrassment by employer

The Appointment letter says the below - 1. Employees Services are liable for termination at any time by giving 1 month’s notice period in writing by the management without assigning any reason. 2. Your required to serve 3 months’ notice period or complete academic year whichever falls later. You are entitled to compensate proportionate gross salary in lieu of the 3 months’ notice not being served . 3. Your also required to complete the academic year as a commitment to the school The academic year completes on May 31. I gave verbal resignation on 1-Oct , written on 24th Dec and worked till 31 Dec . Left due to mental harassment by employer however don’t have any evidence for the same Now company has served legal notice. My questions are A. Is it not one sided contract as employer notice period is only 1 months whereas the entire academic year for the employee. Can I prove this as unreasonable in court. B. Since I resigned in Nov , which is 6 months from end of academic year