No, I claim based on sources that Ostrogoths are not germanic. Ostrogoths are Slavs .
Ostrogoths were goths, a germanic tribe for all we know. Getae (geths) were also of germanic stock who inhabited the Balkans before the Slavic (Sklavines) arrival. It's really not that impossible for them to have been intermixed at some point with one another, but you just can't say that the Ostrogoths were a Slavic tribe. It's historically incorrect.