I think its impossible to get a 9 digit as private keys and i think you are holding only encrypted code you need to find a way tools that can decrypte that can help.. Or maybe you are using some encoder before and you just didn't remember it yet?
You can try this link and decode your 9 digit and maybe you can find here the solution
https://codebeautify.org/base64-decodeYou may also try also the other tools there to decode or decrypt your 9 digit and maybe you can remember that you just encode your private keys or seeds that turn into 9 digit..
Well, that could be a mind wallet phrase, for example if you replace all numbers by words (i.e. "one" instead of "1" etc). But are you sure that this "crypto" is really connected to cryptocurrency?
I don't think I've ever heard of brain wallet, nor do I usually encode. I'm fairly certain it's nothing, but I'm going to throw a thread up in the technical forum to be safe. Absolutely nothing is coming to mind for me for it so if anything I can't imagine it's more then dust.