6 KMnO4 + 18 FeSO4 + 12 H2O → 8 Fe(OH)3 + 6 MnO2 + 5 Fe2(SO4)3 + 3 K2SO4
This is an oxidation-reduction (redox) reaction:
6 MnVII + 18 e- → 6 MnIV (reduction)
18 FeII - 18 e- → 18 FeIII (oxidation)
KMnO4 is an oxidizing agent, FeSO4 is a reducing agent.