3 Cu2IS-II + 20 HNVO3 6 CuII(NVO3)2 + 3 SIVO2 + 8 NIIO + 10 H2O

This is an oxidation-reduction (redox) reaction:

6 CuI - 6 e- 6 CuII (oxidation)

3 S-II - 18 e- 3 SIV (oxidation)

8 NV + 24 e- 8 NII (reduction)

Change the oxidation states