Termination of another family member because of my resignation

I have been working in a private school as a teacher and in the admin department for last 4 years. My mother has been working in the same school for last 19 years. I've submitted my resignation letter to the principal yesterday very clearly stating that I need to leave the city for further studies and today the principal calls my mother in her office stating that she will be terminated too if I decide to leave the job. some points to be considered: according to them, both of us will need to serve the one month notice period, I will not be relieved immediately as insisted. i will not get three months deposit as I'm leaving in the middle of the academic year. my mother will be provided the three months deposit. I don't have any written contract with the school for the current academic year and they also have an issue that I've been interviewing at different schools for better opportunities. the only reason that is given for my mother's termination is that I'm leaving the job. I'd like to know the available lawful actions that I can take against the school. It's a Gujarat Board affiliated school.