We really apologize for all the inconvenience which has caused you.
Are you able to mount other optical media successfully? If you put the Photoshop CS6 DVD in another Macintosh is it able to be read properly? If you can read other discs fine and the disc won't mount on another Mac then it is likely a problem with the DVD.
If the DVD can be mounted on another Macintosh then it is probably an issue with the optical drive on your Macintosh.
Btw if you need the install files you can download the trial from http://www.adobe.com/cfusion/tdrc/index.cfm?product=photoshop. You can then use the serial number included with your software purchase
In the meanwhile if these steps doesnt resolve your issues you can contact Adobe support by following the link below:
But Mandhir, PS6 is not available for download given the new CreativeCloud version. That version did not accept my PS6 version?!?