In which version of unity (personal / plus / pro) available function SSAO ? (screen space ambient occlusion)
As of Unity 5, all versions of Unity have the same in-engine features. Just download the Post-Processing stack from the Asset Store, or any other effect that offers SSAO.
if you refer to the SSAO of the post processing stack this does not exist in the version 2 branch, only in the version 1.
It does exist in the second version, just that it's now been moved to the Post Process Layer component (i.e what you put on your camera), along with AA, presumably because these are two features that are almost always used.