H2O2 (aq) + 4 Na2SO3 (aq) + 2 KMnO4 (aq) → 4 Na2SO4 (aq) + 2 MnO2 (s) + 2 KOH (aq)
This is an oxidation-reduction (redox) reaction:
2 MnVII + 6 e- → 2 MnIV (reduction)
4 SIV - 8 e- → 4 SVI (oxidation)
2 O-I + 2 e- → 2 O-II (reduction)
KMnO4 is an oxidizing agent, Na2SO3 is a reducing agent, H2O2 is an oxidizing agent.
This is a precipitation reaction: MnO2 is the formed precipitate.