I am not able to generate report using TestNG+Intellij 12, also provided out path in Run configuration.
I have even updated to TestNG 6.8 by this way : https://stackoverflow.com
One thing that you can consider to do is, that you check the checkbox under Listeners. This checkbox enables the automated reports. You have to change the default settings of TestNG run options to enable it for any additional runs after the first one. This solved my reporting problems.