Currently there are 45 native Telephoto Prime lenses for Nikon D6 and 35 of these lenses are autofocus (AF) type.
Nikon D6 doesn't have a sensor based image stabilization system but 15 of these Telephoto Prime lenses features optical image stabilization.
Since Nikon D6 has environmental sealings (Weather Sealing), you may like to couple your camera with one of these 21 Telephoto Prime lenses with Weather Sealings.