How do i hook up a NUMARK DXM06 mixer to a PEAVEY XR-600B AMPLIFIER?

There should be an outbound signal on the Numark, either RCA or XLR or maybe 1/4". Plug the outbound signal into the input on the Peavy Amp. You will have to have a cable that will plug into the out of the Numark into the in of the Peavey. Amps usually accept XLR or 1/4" or the newer Speakon connections.