How do two wives immigrate to study abroad?

After your sister has permanent residency, apply for family immigration. As a younger brother, she can't immigrate with your sister. Even they have to queue up to apply for your parents. . If you go to study abroad, it doesn't mean that you immigrate (unless you apply for TR after studying abroad, TR can bring your wife with you) or you can immigrate with skills, and your sister can help you and give you extra points. Then you can come to Australia directly with your wife and children.