Kindly suggest on the matter.
Please check the appointment order - separation clause.
What so ever the reason school might have quoted they are supposed to honour the separation clause which was mutually agreed between the parties.
If your Friend is suddenly asked to move out without any prior notice/intimation/salary in lieu of notice it is unfair labour practice. Your friend can demand for compensation, provided if it is mentioned in the Appointment order.
Therefore, before embarking upon any legal action, the poster's friend may try to negotiate with the management for three month's notice salary.