TiO2 is stable oxide and it is difficult to reduce it. There is Kroll's Process which is performed at 1000°C and it starting with carbon and Cl. With hydrogen it might be more difficult.
There is paper describing use of nitridization instead of chlorification
Article Reduction of Titanium Dioxide to Metallic Titanium by Nitrid...
If you want to prepare Ti alloy instead as TiNi alloy, it is possible to use way with using hydrogen described here:
TiO2 will degrade back to Ti, starting from 500C under oxygen deprived conditions. There will phase change to more stable Rutile as well during high temperature processing. You may want to consider this phase change as well, might be important to your application, if you seeking surface related reduction. More importantly what sort of TiO2 you have, powder, nano crystal, thin film ? Those are all will be effective in the process of reduction.
i calcinate Ti powder at 600C in Air atmosphere. actually i am not sure if Ti will oxidise at this temperature or not. but as i observed that the sintered particles are not conductive, so i supposed that they are oxidised.