I hate this, why can't I just email Adobe a simple question!!!
Want to know can I use the old CS 5 on my new iMac??
As per System requirements | Photoshop, PS is not officially supported on Maverick and you might face several compatibility issues as well. However, we have many users who are still using CS5 on Mavericks. So, if you want you can give it a try and check it for your self.
As far as CS6 is concerned, you can get PS CS6 perpetual version easily from Adobe.com Creative Suite 6
Hope that Helps!