I gave up my rights in court to see my son,can I undo this.

First, it is not a good idea to piggyback your question on another thread. To avoid confusion I've moved your question to its own thread.

However, did you bother to read the notes in the thread you posted to? I ask because there were questions asked that indicated info we need to help you. Like location, laws vary by area. Like what were the circumstances of your giving up your rights? Generally if a court terminates parental rights they are not recoverable.

If you want help you have to give us facts that we can use to formulate an answer for you. We can't give you an answer based on what little you posted.