What is the role of the director of the F. B. I

The role of the FBI director is generally more administrative than anything else, so they mostly oversee the operations everyone else is working on. They're also responsible for speaking on behalf of the FBI to the president or whoever else they may need to address.

The Director is responsible for making sure that cases and operations are handled correctly. The Director also is in charge of creating leaders in any of the agencies with qualified agents.