2 CrIIII3-I + 64 KOH + 27 Cl20 2 K2CrVIO4 + 6 KIVIIO4 + 54 KCl-I + 32 H2O

This is an oxidation-reduction (redox) reaction:

6 I-I - 48 e- 6 IVII (oxidation)

54 Cl0 + 54 e- 54 Cl-I (reduction)

2 CrIII - 6 e- 2 CrVI (oxidation)

Change the oxidation states