Tola was identified according to his tribal identity (from Issachar). But for Jair we are not told his tribal identity. Instead, he is presented to us as the representative of a region: After him arose Jair the Gileadite.
This suggests that his judgeship covered multiple tribes, at least the tribal allotments east of the Jordan.1
3 After him arose Jair the Gileadite, who judged Israel twenty-two years.