Most likely, the only marsupials in Austria would be in zoos. Austria has 8 zoos. I found no way to count how many marsupials they have. The Alpenzoo specialises in endangered Alpine species - acting as a Noah's ark - but also reintroducing local species back into the wild. The Herberstein Zoo has at least two kangaroos, though they look more like cold climate Rock Wallabies to me. Salzburg Zoo keeps the rare Parma Wallaby. The Schmiding Zoo has a few Red Kangaroos. The Tiergarten Schönbrunn in Vienna is the world's oldest zoo, with over 700 species of animals from every continent. I would guess that they probably have at least one kind of kangaroo or wallaby but I could find no records or images of any.
I found I could not discover exactly what marsupial species or how many individuals of each kind are kept in Austria. It seems that various kinds of Australian birds are far more commonly kept there.
I do know that the Australian government is extremely picky about allowing our marsupials to be exported, especially those that are most at risk of extinction. China has quite a large collection of our koalas in return for allowing us to be part of the world-wide Panda breeding program.
I know you probably intended this question to be a joke, Ele, but I thought it was worth a crack to try to find the answer. Sorry I failed.
SpunkySenior 