What are the rights of woman if her husband divorces her?

My dad is having an extra marital affair, and threatens my mom that he will not look after her or me and my siblings which is very concerning as he is the sole bread winner in the family. My mother also went through an episode of depression due to the same but he still continues to threaten her. What is the best possible way to tackle this situation also can the person with whom he is having the affair claim his property?? What will be rights of my mother in case of a divorce?