Sure they can, coz kangaroos are vegetarian. Btw some /if not all/ meat factories in Russia import kangaroo meat from Australia and use it in their production. Щай гьикъулей дуца?)

Well, kangaroo meat is generally harvested (ie. hunted) - actual farms are few and far between. I'm not sure if, or how, the harvesting of kangaroos falls in line with halal principles. I found one page which declared kangaroo meat may be consumed by Muslims, but I still couldn't find the connection which makes it legitimate. This would need a good deal of research!