My father just died. As I took care a lot of him, my brother agrees to waive the succession for all the goods of our dad back to me. Is it possible ?

Not if your brother has children, because in this case they come in representation of their giving father. In other words, they take the place of their father in the estate and collect the property of their grandfather.

Also, if the property belonged to your parents, your brother waiver (provided that it has no descendants) would work only for your father, not your mother's.