Let the oxidation states of three Br atoms be \( x_1, x_2, x_3 \). The total oxidation state of oxygen is \( -12 \) (since 6 O atoms at -2 each).
So, \( x_1 + x_2 + x_3 - 12 = 0 \Rightarrow x_1 + x_2 + x_3 = +12 \).
Structure-based oxidation states: Br atoms show +6, +4, and +6 respectively.