hey ketab,
there are in fact a lot of download extensions available for joomla in general, you can check them out at the JED http://extensions.joomla.org and see which one fits you best.
however I haven't heard of a ready integration directly into easysocial but I know the guys at jdownloads http://www.jdownloads.com are working on it (currently beta).

hope that helps and have a nice day

Thank you Alex, i'd just taked a look @ JED, downloads/directory section where i founded many extensions,
i am looking to create a downloads section where membres share some files, not only me !

regards

Hello Ketab,

In EasySocial groups, it's already possible to share files via the file apps for groups. However, if you are looking for component wide, you need to look at JED