In PS belielieve you have Help/about plugins/camera raw if you first click on About Photoshop
Most camera raw problems are having the plug in in wrong folder, or more than one file in the folder.
Think it would be hard to download ACR 7.1 if using CS6 as that version is way old. Usually the latest version is offered, as it includes all the info from the previous versions also.
I finally got mine working.
And I don't think cs 6 is too old.
Anyway, I reinstalled ps cs6.
Then I updated. There was a problem with dynamic link but I was able to fix that as well.
The updates only gave me 7.0 so I downloaded 7.1 and tried that with the same result as before.
So I downloaded 8.3 and Voila! Success.
I hope that helps.