Ideally, around 60-65%. Curing can happen ONLY AFTER proper drying. If you improperly dry the buds, then they will never be able to cure. You overshot your window of opportunity. So, if you have already over-dried your buds, then there isn't any point in trying to cure them because it won't happen.
In the future, you need to dry the buds slowly in a dark room with just a small fan moving the air -not blowing on the plants. Once they are dry...but not too dry...you transfer them to a curing jar and then proceed to burp the jars for several weeks. If you have too much moisture left in the buds when they go into the jar, then you get mold and the whole thing is ruined and unsmokeable. If you don't have enough moisture in the buds then the curing process will not happen. It's a matter of getting it jusssssssst right. That may take some time to learn. Curing is an art...but it's not rocket science. There are all kinds of videos and tutorials about curing out there.