if the delinquent has accepted the charges, then there is no need to conduct an enquiry, but you can award punishment appropriate to the charges. If the misconduct is very severe, he can be dismissed from service. On the other hand, if the charges is not severe then you can retain him but after awarding a lesser punishment. It shall include stoppage of increment for one or two years (with cumulative effect or without cumulative effect), demotion, warning or any other punishment that you decide. Normally, the severity of misconduct as to whether the misconduct is major misconduct or minor misconduct, and what are the punishments that can be given will be elaborated in the standing orders of the company. Then it will be easy for you to proceed in a better way.