3 Ti0 + 4 HNVO3 + 12 HCl 3 TiIVCl4 + 4 NIIO + 8 H2O

This is an oxidation-reduction (redox) reaction:

3 Ti0 - 12 e- 3 TiIV (oxidation)

4 NV + 12 e- 4 NII (reduction)

Change the oxidation states