10 FeIICl2-I + 6 KMnVIIO4 + 24 H2SO4 5 Fe2III(SO4)3 + 10 Cl20 + 6 MnIISO4 + 3 K2SO4 + 24 H2O

This is an oxidation-reduction (redox) reaction:

6 MnVII + 30 e- 6 MnII (reduction)

20 Cl-I - 20 e- 20 Cl0 (oxidation)

10 FeII - 10 e- 10 FeIII (oxidation)

Change the oxidation states