Murchison Gorge , could be.
Looking at the vegetation I think its tropical or sub tropical, possibly spinifex grass near where he's standing and possibly a Kapok bush also.
Its fairly typical of the tropical gorges being scoured clean by very high water flows, it could be just geology affecting the vegetation but I think you can see an old high water mark 20 or 30m up on the left hand side.
Not Carnarvon Gorge Qld, unless its the very high reaches, Porcupine Gorge I think its called.
Not Kings Canyon at all.
Very reminiscant of Murchison gorge WA, very.
I doubt Katherine Gorge, unless its one of the side canyons.
Its possibly in the Kimberley but I don't think so.
Not the Pilbara, Whittenoom etc, not red enough.