Arkansas public colleges and universities charge you in-state tuition even if you are not an Arkansas resident, if you are a recently separated veteran, a current service member, a contracted ROTC cadet, or the spouse or child of one.
Contact the admissions or registrar office at the Arkansas public institution you plan to attend and ask them to classify you as a resident for tuition purposes.
Your DD214 showing an honorable discharge and your service dates, or your military ID and orders if you are still serving, plus proof of your relationship if you are claiming as a spouse or child.