How can I install photoshop cs6 on ubuntu 14.04?

Step 1. Install the Wine Team Ubuntu PPA
First start by installing Wine btw it's a utility to install windows apps in linux :
open the Terminal and :

   sudo add-apt-repository ppa:ubuntu-wine/ppa     
   sudo apt-get update && sudo apt-get upgrade
   sudo apt-get install wine1.7 winetricks

Step 2. Using winetricks to get install dependencies for Photoshop CS6
Now that we have the most recent build of wine, we can get started on fetching the necessary build packages to run the Photoshop installer.
Here’s the command to issue and pull those dependencies

winetricks atmlib gdiplus msxml3 msxml6 vcrun2005 vcrun2005sp1 vcrun2008 ie6 fontsmooth-rgb gecko

If a few errors pop-up, don’t worry – chances are this install will still work.
Step 3. Running the Photoshop CS6 installer
Now that you have all dependencies required to run Photoshop CS6, you can now run the Adobe setup. Either right click Setup.exe, or from the terminal:

   cd /home/user/path/to/installer    
   wine Set-up.exe

If everything worked as intended, you are now done. Photoshop should install like any other program via wine – It should even automatically appear in your programs list!