The Yugoslav Navy was pretty small in 1941 and the Navwar pack contains the only 5 vessels that were of any real size, an ageing ex-German light cruiser, a British built destroyer leader and 3 french built destroyers. The cruiser was very old and not much use for anything but training, the four destroyers however were modern and effective. Yugoslavia was quickly overun by the axis and most of her fleet ended up serving with the Italians.
First up the light cruiser Dalmacija, of German origin where she was known as the Niobe.
The Destroyer Leader Dubrovnik
And the three destroyers of the Beograd class: Beograd, Zagreb and LjubljanaAnd finally here is the link to the PDF I've done with the stats for the above ships.