Can my husband take my kids without my permission?

Somebody has to file for divorce and custody, otherwise you will both be in this limbo until a court decides. If there is no custody order, then yes, he probably can enroll them in a different school. You may be able to get a court to remand that decision, but you will still have to go to court. So do it now. I suggest you talk with an attorney to determine what your options are.

If you have court orders, read them and see what it says. If not, perhaps you should see an attorney and get some.

If you are simply living apart and there are no court orders, he has an equal right to custody and possession of your and his kids. They are his kids too and you "took them away from him" in his mind. You need to obtain a court order of custody for the kids in order to control where they go to school without his consent.

It is not clear from your facts whether you are separated or not, and if you are, whether you have a written agreement or court order in place. That would be helpful to give you better advice, and eventually you should consult with an attorney anyway because it sounds like this may unfortunately be heading for litigation if the parties are no longer amicable and nothing has been resolved yet.