It's his house... even if your mom pays some rent, it depends on whether your mom will risk family discord, or losing the home you live in, in order for you to own snakes.
You should talk to your mom, and see what can be done. Sometimes the out-of-sight-out-of-mind works. If he doesn't see/hear/smell snakes, he may just sort of let it slide. Keep them up in their cages, in your room, and hope for the best. It's part of living with parents/family, that sometimes things don't go your way.
Good luck.