3 KMnVIIO4 + 5 NIIO + 3 H2SO4 2 HNVO3 + 3 MnIISO4 + 3 KNVO3 + 2 H2O

This is an oxidation-reduction (redox) reaction:

3 MnVII + 15 e- 3 MnII (reduction)

5 NII - 15 e- 5 NV (oxidation)

KMnO4 is an oxidizing agent, NO is a reducing agent.