Yes bit up to the judge. My step daughters mom was in jail for 4 years. Her daughter was taken at age 1 because she was found in a meth house. Husband has private investigators out looking for his daughter for 6 months no one could find her. When mom wa sin jail she waived all parental rights. When she was released she never contacted for a long time when she found out I was raising her daughter she flew in so fast to be her mom and the judge said sure why not. Stupid judge thats when all the problems in our house slowly started to fall apart.

He can file for whatever he wants. Whether he will get custody is up to a judge. If he relinquished his rights, he will have a really hard time regaining custody. Did someone else adopt the child?

Once a person loses their parental rights, whether by force or willingly, they have no rights to custody, communication, contact, information, etc regarding the child. If the rights were terminated legally by the judge the court will have no choice but to deny the request of custody and a hearing won't even be set and if it is, once the evidence is presented that rights were terminated it will be denied. Ask assistance from a reputable family law attorney in your area. Most will give a free consultation and answer basic questions. Best of wishes!