The problem is that the version of ACR (Adobe Camera RAW) that your version of Photoshop has is out of date and sadly can't be upgraded to the latest version. So unfortunately you have only have a couple of options.
1. Upgrade to the latest version of Photoshop
2. Buy Lightroom or Aperture (if you have a Mac)
3. Use Adobe DNG converter
Adobe - Digital Negative (DNG)
EDIT: Before anyone jumps down my throat there are other applications other than Photoshop, Lightroom and Aperture that could process your NEF files, your camera may even have come with some software and of course Nikon also do their own Capture NX2 software
Adobe DNG is your cheapest option because it's free. The idea is that you use this to convert your NEF's to DNG's which you can then edit in Photoshop.
HTH