Try this installer for camera raw 8.3
http://swupdl.adobe.com/updates/oobe/aam20/win/PhotoshopCameraRaw7-7.0/8.3.52/setup.zip
If the above doesn't work, you could download the 8.3 dng converter and install it.
That installs the needed profiles for camera raw.
8.3 DNG Converter:
Adobe - Adobe Camera Raw and DNG Converter : For Windows : Adobe DNG Converter 8.3
Then download this 8.3 camera raw plugin and replace the existing camera raw plugin in cs6 with the one in the zip that you downloaded.
Adobe Camera Raw Help | Camera Raw/DNG Converter 8.4 on Mac OS 10.6, Windows XP, and Vista