Print Seperation Color with Illustartor CS6

Hello everyone, in the company where you work we have Illustartor CS6 available.
The point of the situation is that I have to create a file with color separations inside. As we all know, to do this you have to do "print" and then put "Adobe PostScript" and put in Output : Sepration. Well, the separation part is off and I can't click anything. How should I do? Do I need to install anything?