Reliving from Service after resignation

My daughter is a general surgeon and working with a Central Government Super Specialty Hospital based in Kolkata for last 6 months as Senior Resident doctor. This is a tenure post and the appoint is for one year. It is clearly mentioned in the contract of employment that “One month’s notice or in lieu of one month’s salary from either side will be required in case of termination or resignation from the institute.” She was continuously discriminated and harasses by the consultant. Finally she decided to quiet the job and move to other place. Although she has couple of evidences of plotting conspiracy and alleging her negligence on duty and not giving rounds on weekly off day (Sundays) even if there no serious patient in wards or there is no emergency situations. In case of emergencies she never defaulted which has proofs in patient’s files and biometric records besides what’s app messages and record of phone calls. In all probabilities the management was aware about all this to certain extent. We decided not to complain to authorities outside only because taking any action will go against the individual and the institute as well. This will spread out and people with start forming an opinion against her. She tendered her resignation on 11th May 2022 saying “Please accept my resignation for the services of the institute with effect from 12th May 2022 (From Next working day). She was ready to forgo one month’s salary. She was called by the Director and asked to explain the reason. He was appraised about the problems. The director asked her to meet next day. Next day, The Director said that sudden resignation goes against the institute so you need to serve one month notice. Still you wish to go from immediate effect, we will not provide you any reliving letter and experience certificate. Finally she agreed to serve one month notice period which will end on 11th June even after knowing that she is being forced or blackmailed on pretext of reliving documents. Even she has not been paid her stipend for the month of April 2011 till date. In recent past few of her senior resident colleagues have resigned and gone but none of them have been given reliving letter and experience certificate. I am worried, if this happens to her, she would not be able to join nest job. Secondly please advise can we make a complaint to any authority with involving police and court so that there practices stops and others do not suffer who are still working there.