Voluntary termination of parental rights

My son has been paying for child support since his daughter has been born, he lives in TN she and the child live in Ohio. He has not been able to contact his daughter, has not seen her since her birth and has no idea of an address, has not seen a picture, can not contact her mother.

Other than the child support being a financial hardship on him and his son of six years is there anything he can do to end the financial support?

I can understand if he and his daughter even knew each other, had some sort of relationship but there is none, there never was even after several attempts to meet her and get to know her her mother has denied any and all attempts over the years and there is no visitation Order attached to the support order.

What can his options be?