The answer is certainly "yes" if you have received demands in te last 6 years. If they have never asked for the money in the last 6 years (unless you faield to give them your new addres) you still owe it but maybe (only maybe) the debt may be statute barred in certain circumstances
If a person has a debt which they haven't acknowledged for a six year period then the debt, legally speaking, doesn't have to be paid back although the debt still remains. However, a court fine is different and you will have to pay it back.