The reaction XeF4+O2F2→XeF6+O2 is an example of a redox reaction.
The oxidation number of Xe increases from +4 in XeF4 to+6 in XeF6. Hence, it is Xe is getting oxidised.
On the other hand, the oxidation number of oxygen decreases from +1 in O2F2 to 0 in O2. Hence, it is getting reduced.