6 NaI-I + 2 KMnVIIO4 + 4 H2O 3 I20 + 2 MnIVO2 + 6 NaOH + 2 KOH

This is an oxidation-reduction (redox) reaction:

2 MnVII + 6 e- 2 MnIV (reduction)

6 I-I - 6 e- 6 I0 (oxidation)

KMnO4 is an oxidizing agent, NaI is a reducing agent.