K2Cr2VIO7 + 3 SIVO2 + H2SVIO4 Cr2III(SVIO4)3 + K2SVIO4 + H2O

This is an oxidation-reduction (redox) reaction:

3 SIV - 6 e- 3 SVI (oxidation)

2 CrVI + 6 e- 2 CrIII (reduction)

Change the oxidation states