Do I need a lawyer

You should get a lawyer and file for custody in Ohio in the same court that gave custody to your mother. Use the same case number. Your mother can voluntarily relinquish custody to you; however the judge does not have to give you custody just because the two of you want it. Depending on the reasons why custody was taken from you in the first place, the court will want to make sure that the custody change is in the best interests of the child. This is done by appointing a guardian ad litem.