5 HNIIIO2 + 2 HBrVO3 5 HNVO3 + H2O + Br20

This is an oxidation-reduction (redox) reaction:

2 BrV + 10 e- 2 Br0 (reduction)

5 NIII - 10 e- 5 NV (oxidation)

HBrO3 is an oxidizing agent, HNO2 is a reducing agent.