In the last episode of the Clone Wars cartoon series, Ashoka Tano was accused by the Jedi Council and put out of the Order, but after some diligent research, Anakin found out who was the real culprit, so Ashoka's name was cleared.
The Jedi Order asked her to return, but she declined their offer.
So, uh, what happened to her after that? Wookiepedia does not say.
I asked this question before Rebels even came out, back when there was really no information to be had save for some hearsay. There is so much information now about Asokha that there's no reason to ask a question like this any more.
So, when you read this, please keep in mind that the question is dated.