Cr2IIIO3 + 10 KOH + 6 NIVO2 6 KNIIIO2 + 2 K2CrVIO4 + 5 H2O

This is an oxidation-reduction (redox) reaction:

6 NIV + 6 e- 6 NIII (reduction)

2 CrIII - 6 e- 2 CrVI (oxidation)

NO2 is an oxidizing agent, Cr2O3 is a reducing agent.