3 IIIICl3 + 6 H2O 2 HIVO3 + HI-I + 9 HCl

This is an oxidation-reduction (redox) reaction:

IIII + 4 e- I-I (reduction)

2 IIII - 4 e- 2 IV (oxidation)

ICl3 is both an oxidizing and a reducing agent (disproportionation).