3 Br2 (aq) + 6 KOH (aq) → 5 KBr (aq) + KBrO3 (aq) + 3 H2O (l)
This is an oxidation-reduction (redox) reaction:
5 Br0 + 5 e- → 5 Br-I (reduction)
Br0 - 5 e- → BrV (oxidation)
Br2 is both an oxidizing and a reducing agent (disproportionation (dismutation)).