HBr (aq) + 7 KOH (aq) + 3 Cl2 (g) → KBrO3 (aq) + 6 KCl (aq) + 4 H2O (l)
This is an acid-base reaction (neutralization): HBr is an acid, KOH is a base.
This is an oxidation-reduction (redox) reaction:
Br-I - 6 e- → BrV (oxidation)
6 Cl0 + 6 e- → 6 Cl-I (reduction)
HBr is a reducing agent, Cl2 is an oxidizing agent.