(a) This state and Indian tribes are authorized to enter into agreements with each other respecting care and custody of Indian children and jurisdiction over child custody proceedings, including agreements that may provide for orderly transfer of jurisdiction on a case-by-case basis and agreements that provide for concurrent jurisdiction between the state and Indian tribes.
(b) Such agreements may be revoked by either party upon written notice of one hundred eighty (180) days to the other party. Such revocation does not affect any action or proceeding over which a court has already assumed jurisdiction, unless the agreement provides otherwise.