The Nytro rails mount the front and rear arm in the same location as the Apex, so the Apex rails should work they are just longer.
The Nytro front and rear arm are narrower though, so they would not interchange easily.
KMOD
I am putting a Nytro skid in my RX-1 and put the skid side by side with my Apex Mtn skid and they look identical. Mounting points are the same, with the longer rails you will need to order one cross brace for the rear and that's the only difference I can see. It is slightly narrower, looks like about a 1/4".
the apex rails fit on a RX-1 i do know that for sure..and by looking it looks like the nytro has suspension very simalr to the rx-1 but i would do some measuring to make sure...they should fit tho