I think it’s just 3-4 in each direction, so if so something bad and you’re old, it would affect your grandkids, and if you’re young it would affect your grandparents

as rumor suggests

From Wikipedia:

Numerous testimonies of North Korean defectorsconfirm the practice of kin punishment (연좌제, yeonjwaje literally “association system”) in North Korea, under which three to eight generations of a political offender’s family can be summarily imprisoned or executed.