My husbands exs wants to sign her rights away to her dad and step mother but the mothers dad has a pretty intence police record and I jusdty want to know if the father gets the final say so in the matter of the child

First, please pay more attention to posting guidelines. There is a Read first sticky on the top of the Children forum (where this was moved from) that directs legal questions here.

Second, I'm not sure I follow your question. A parent cannot just sign over their rights. Only a court can terminate parental rights (TPR) and courts are very reluctant to do so. Generally they will only do so to clear the way for an adoption or if the parent represents a danger to the child.

It sounds like you are the step mother, are you prepared to adopt the child?