2 NaBrO3 (aq) → 3 O2 (g) + 2 NaBr (aq)
This is an oxidation-reduction (redox) reaction:
2 BrV + 12 e- → 2 Br-I (reduction)
6 O-II - 12 e- → 6 O0 (oxidation)
NaBrO3 is an oxidizing agent, NaBrO3 is a reducing agent.
This is a gas evolution reaction, O2 is the formed gas.