Depends what you mean by fibre. All Internet uses fibre somewhere on the network, and many ISPs add the "fibre" label to anything they deliver.
But if this is fibre to your property, the modem bit probably won't work. That's for DSL.
You can use the D6220 as a router by connecting whatever delivers your Internet to the red Internet port on the back of the modem/router.
There is support for the D6220, including a manual, somewhere at the end of this link:
>>>> D6220 | Product | Support | NETGEAR <<<<
