6 NaHSO3 (aq) + 4 KMnO4 (aq) → 3 Na2SO4 (aq) + 4 MnO2 (s) + 2 K2SO4 (aq) + H2SO4 (aq) + 2 H2O (l)
This is an oxidation-reduction (redox) reaction:
4 MnVII + 12 e- → 4 MnIV (reduction)
6 SIV - 12 e- → 6 SVI (oxidation)
KMnO4 is an oxidizing agent, NaHSO3 is a reducing agent.
This is a precipitation reaction: MnO2 is the formed precipitate.