In CO82 only after creating the number ranges you need to assign it to group.Go to change group fist select the group and then click on your order type and select select element symbol and then click on element\group and then save it.
refer this link
hope it helps
Select change groups. Goto menu group insert, enter the group name ans the number range which does not exists, i.e., no overlaps with the existing numbers.
double click the order type for selection and check the box of the group to which the order type to be assigned and press F5.
Go to OPJH select your order type go in details and you will get number range tap click on it and assign number range here.
Or goto CO82-> select Groups(Pen icon) - >select ur order type from under Group name and-> select Maintain (pen icon) .u can define number range for ur order type.
Examaple order type(YB01) from Not assigned section-> select Group check box(Prod order) to which order type to be assigned -> then select assign /element Group (F5),