Calling AmyMyBlueFront - Jim..... Jim's BFA, who is 30+ yrs old, all of it with Jim, will only step up on a piece of branch. You must not give up, go back to ground zero if needs be, several times. Reason I say this, is that Ringneck can go back to the 'wild' state rather quickly, if left alone in a cage for a short period of time.
He obviously wants to be with you, you just have to figure out why he is not going to a finger or hand. Possibly he fell from a hand, or was roughly treated by a hand. You never know. What you go know is the little guy is likely confused a bit. SO you start from scratch. sit by his cage nd read to him, anything will do. Offer a treat tru the bar now and then. Oh BTW, find his most favorite treat - that is ONLYused in training, not other times. SO he will look forward to your 'sessions' with him for no other reason. After a week of ths, try getting him to step up on the hand held perch, or piece of branch, by offering the teat, but make it so the bird can only get to it by standing on the perch. A week of that, and try moving the perch outside the cage with him on it, offering the treat as you go. It may be a steady stream of treats, each bird is different. Lots of praise too.
Lets say that this works, but he grabs the outside of the door in tryin to get him out. That may require going back to stage one. But dont give up.
Ring necks can be so cuddley if they really trust the person. Dont rush anything, you have the rest of his life ( not yours) to learn this basic requirement (trick) . Good luck. Post lots off pics, we love them, and they can show us stuff that words leave out.