RSA 170-C:3: Jurisdiction.

The probate court shall have exclusive original jurisdiction over petitions to terminate the parent-child relationship when the child involved is present in the state or is in the legal custody or legal guardianship of an authorized agency located in the state. The petition shall be filed in the probate court of the county in which the child or his parents reside at the time of filing of the petition, or in the probate court of the county in which the authorized agency has provided services to the child.