Hi abjith ,
Thanks for your questions.
As far as we know, it shouldn't affect Google Analytics. Any of the thousands of users of ATUM free have never reported any incompatibility between both plugins.
Regarding Polylang, I can't assure you that, but while using ATUM free, you shouldn't have any problem. However, if you're going to use any of our premium plugins, probably it won't work.
You can find here a list of the third-party plugins that we support.
Please note that as we say in that article, this does not mean that it cannot be compatible with more plugins, it simply means that we have not tested this compatibility with other plugins.