I can not open RAW files from my D90 in CS6 on my MAC. I keep getting the message "Could not complete your request because Photoshop does not recognize this type of file." I downloaded the 7.3 Raw update and still get it and am getting when I try to open any type of photo. I am new to MAC and CS6 so it could just be me. I used CS5 on a Windows PC for 3 years and never had trouble. Thank you!!
The D90 is supported by all versions of ACR that run with CS6.
Your image files could be damaged. This can be the case if you used the Nikon Transfer to copy the files from the card to your computer, as the Nikon utility is known for corrupting the image files on the Mac.
Use either the Finder or the Bridge Photo Download to copy the image files from the card to your computer—I hope you still have the originals on the card.
BTW, it's Mac for Macintosh, not "MAC".