If it is not redeemed by the end of a full year, then the house in the walled city is permanently transferred to its buyer and his descendants. It is not to be released in the Jubilee.
KJV
And if it be not redeemed within the space of a full year, then the house that [is] in the walled city shall be established for ever to him that bought it throughout his generations: it shall not go out in the jubile.
ASV
And if it be not redeemed within the space of a full year, then the house that is in the walled city shall be made sure in perpetuity to him that bought it, throughout his generations: it shall not go out in the jubilee.