Fe0 + 4 KMnVIIO4 + 4 HCl FeIII(MnVIIO4)3 + MnIVO2 + 4 KCl + 2 H2O

This is an oxidation-reduction (redox) reaction:

MnVII + 3 e- MnIV (reduction)

Fe0 - 3 e- FeIII (oxidation)

Change the oxidation states