2 KMnVIIO4-II K2MnVIO4-II + MnIVO2-II + O20

This is an oxidation-reduction (redox) reaction:

MnVII + e- MnVI (reduction)

MnVII + 3 e- MnIV (reduction)

2 O-II - 4 e- 2 O0 (oxidation)

Change the oxidation states