5 HNIIIO2 + 2 HBrVO3 5 HNVO3 + Br20 + H2O

This is an oxidation-reduction (redox) reaction:

2 BrV + 10 e- 2 Br0 (reduction)

5 NIII - 10 e- 5 NV (oxidation)

Change the oxidation states