3 CuIIS-II + 10 HNVO3 3 CuINVO3 + 7 NIIO + 3 H2SVIO4 + 2 H2O

This is an oxidation-reduction (redox) reaction:

3 CuII + 3 e- 3 CuI (reduction)

3 S-II - 24 e- 3 SVI (oxidation)

7 NV + 21 e- 7 NII (reduction)

Change the oxidation states