He is upside down he is still breathing but is jus floating around. The oscar bit him and it started, it doesnt even look like he bit him that bad. Is the poor bala doomed?

Honestly sounds like the bala is injured badly. More than likely his only hope is a hospital tank. Now that he is in this shape he may suffer more attacks.

How big are the fish and the tank?

so how did it play out? was the bala just stunned or was it a mortal wounding?

if any fish is floating and breathing heavily on the surface of the tank.. especially with a huge bite from an oscar never-the-less, the future is never good..

id maybe TRY to medicate him... but be aware that the odds are that the bala wont live

*hugs* good luck