Can a chemical reaction have two balanced equations?
You can expand the second equation so it has the same amount of educt on the left side as the first one:
$$\ce{6XeF4 + 12H2O → 3Xe + 3XeO3 +  24HF + 1.5 O2}$$
Difference on the product side, compared to first equation, is
$\ce{-1 Xe + 1 XeO3 - 1.5 O2}$.
This excess of one $\ce{XeO3}$ can go
$$\ce{XeO3 → Xe + 1.5 O2}$$
, exactly the amount of xenon and oxygen that was missing compared to the first equation.
Your equations describe not one reaction, but (at least) two, which don't have to occur in a predefined proportion. It's not directly clear, and would involve an in-depth investigation, what exactly the elementar reactions are.
So you could make an infinite number of chemically correct, but quantiatively different equations for the hydrolysis of xenon flouride. All depends on the reaction conditions, probably.