DCC Get Folders This allows you to specify dcc get directories where received files will be placed according to their extension. Files which don't match any of the extensions you specify are placed in the default get directory.
i think the problem is that you are using the wrong place to do what you want. If you have .rar ignored as a file type, then in that option where you see DCC get folders, look under "DCC IGNORE". Go to "Ignore all except", click on add and then put *.rar