Test it on a series of rootstocks and see where performance is best. It is possible to pursue variety protection on clonal germplasm. Congrats, you are a private breeder!
If it has some good qualities cross it into other elite varieties too. It probably won’t do much good, but you never know, and it takes a long time.
Connect with an apple breeder. I know a few good ones you can trust that would be glad to offer advice. Good luck.