I need to use Talend Open Studio with a SVN. What is the folder that I should put in the repository?
Well, the "official" answer is to upgrade to Talend Integration Suite (TIS), which includes SVN integration. It goes a long way to synchronizing the activities of several developers using a shared repository.
If TIS is not an option for you, you might have some success by putting the project directory of your Talend Open Studio (TOS) under SVN control. This is the directory immediately under "workspace" that has the same name as your project. You would have to perform all SVN operations, such as commit and update, manually on this directory, for example using Tortoise (if you're on Windows). TOS might be able to use this project as if it was not under SVN. I personally haven't tried this, and would recommend using TIS instead.