2 HBrIO + HNIIIO2 HNVO3 + H2O + Br20

This is an oxidation-reduction (redox) reaction:

2 BrI + 2 e- 2 Br0 (reduction)

NIII - 2 e- NV (oxidation)

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