According to this -
Camera Raw plug-in | Supported cameras
You need at least Camera Raw 7.1 before CS 6 will support D800 NEF files.
With CS 6 open click on
Help > Update to get the most current CS 6 Camera Raw release. - 7.4 I think.
Here is how the release and update numbers work:
Camera Raw was first available with Photoshop 7.
After Photoshop 7 Adobe changed the next release of Photoshop to the new name - Photoshop CS (Creative Suite).
Photoshop CS (Photoshop 8) uses Camera Raw 2.x
Photoshop CS 2 (Photoshop 9) uses Camera Raw 3.x
And so on, so CS 6 (Photoshop 13) uses Camera Raw 7.x.
CS 6 has been superseded by Photoshop CC (Photoshop 14/Camera Raw 8) and will get no further Camera Raw 7.x updates.
Already CS 6 does not support the NEF files of the Nikon Df, D5300, and D610. To open Nikon Df, D5300, D610 files in CS 6, they need to be converted to the DNG file format.
Adobe - Adobe Camera Raw and DNG Converter : For Windows
Adobe Bridge was first available with CS 2.
So CS 3 (Photoshop 10) uses Bridge 2, and CS 6 uses Bridge 5.
CC uses Bridge 6.