4 HINIIIO2 + S0 H20 + 4 NIIO + H2ISVIO4

This is an oxidation-reduction (redox) reaction:

S0 - 6 e- SVI (oxidation)

2 HI + 2 e- 2 H0 (reduction)

4 NIII + 4 e- 4 NII (reduction)

Change the oxidation states