N.H. Rev. Stat. Ann. § 560:14

The waiver or release of the will and homestead right provided for in RSA 560:10 shall be made in writing and shall be filed in the probate office within six months after the appointment of an executor or administrator, and not afterwards, unless by permission of the judge of probate for good cause shown. Where real estate is involved, the waiver and release shall be recorded in the registry of deeds of the county where the real estate is situated.