Hello there! 9.6 would be the latest one. You can get this version by going to the appstore and looking for OSX. Then upgrade your system to latest version for free and you will have latest iphoto app on your mac.
The above is a direct link to the upgrade.
Hello again. I am posting back because i have not heard from you hopefully this a good thing as your problem is possibly fixed. Please either post back if your still having problems or just rate this reply