My son has a daughter,and he is incorserated,The mother of the baby is on drugs and her mom need my son to give up rights to her,Does that mean he will not be the father anymore,and will he be able to have father rights after he gets out?

First, you start with an incorrect assumption. That he can just give up his rights. Only a court can terminate parental rights and they are very reluctant to do so. However, if the mother is trying to put the child up for adoption, then yes he can agree to it and all rights he has to that child will be severed.

If she is not putting the child up for adoption, then he will not be able to sign over his rights. So when he gets out, he can petition the court for visitation.