my son is in DHS custody in Arkansas if I were to sign over my rights can my grandparents adopt him right now

My son is in DHS custody in Arkansas due to false allegations cuz he had a brain bleed. My grandparents in in process of completing steps to get him placed with them. My rights are going to be terminated due to criminal charges over this. If me and the child's father were to willingly right now sign a termination of rights with my grandparents lawyer can they adopt him even though he's in DHS custody. They have already completed the home study and background check. They also raised and adopted my baby brother