You have stated that your wife resigned from her job at a school due to the misbehavior of the administration. Legally speaking, there was no need for her to resign, as she could have brought the issue to the attention of the Head Master/Head Mistress/Principal or the Secretary/President of the school, highlighting the conduct of the administration.
Anyway, since she has already resigned, she will need to submit a detailed letter outlining all the facts that led to her resignation. If any of her colleagues can serve as witnesses or provide support for her case, it may increase the chances of her reinstatement at the school, or the management may reconsider the notice period based on the circumstances.
In cases of sexual harassment, you can file a First Information Report (FIR) against the concerned administrator at the relevant Police Station. Based on the facts presented, they will take appropriate action against the administrator.
Thank you.