Oppo Reno 5 pro has a 6.55inch FHD+ Super AMOLED Display with a 90Hz refresh rate while on other hand Xiaomi Mi 10T pro has a 6.67inch FHD+ IPS LCD with 144Hz adaptive refresh rate.
If I have to choose one I would choose Oppo Reno 5 pro as it has a combo of Amoled and a higher refresh rate which is much better than an IPS LCD with a much higher refresh rate.
Winner — Oppo Reno 5pro
Here Oppo Reno 5 Pro comes with a Mediatek Dimensity 1000+ which is a great performer in the given price range from MediaTek while Mi 10 pro has Snapdragon 865 plus in it. Well if I talk about CPU performance Snapdragon 865 Plus has the advantage over Dimensity 1000+ but in gaming, the situation is kinda similar as both can run games in max settings with excellent fps stability. While in day to day task its difficult to see performance difference in both devices but if we talk about benchmarks then Snapdragon 865 plus has the upper hand.
Winner — Xiaomi Mi 10T Pro
Reno 5 Pro has a 64Mp+8Mp(Ultrawide)+2Mp(Monochrome)+2Mp(Macro) Quad camera setup while Mi 10T pro has a triple-camera consisting of 108Mp+13Mp(Ultrawide)+5Mp(Macro).
From the primary camera, you can take great pictures from both of these devices. If I talk about a Secondary camera than Mi 10T pro is a better choice here as it has a 13Mp ultra-wide lens for detail picture compared to just 8Mp of Reno 5Pro. In the video, Reno 5Pro has its advantage over Mi 10T pro has that it has AL highlighted video features that can enhance video quality in low light.
Overall both phone have a great camera.
Main camera performance winner — Oppo Reno 5 Pro & Xiaomi Mi 10T pro.
Versatile Camera winner — Xiaomi Mi 10T pro
Better Video Performance — Oppo Reno 5 pro.
Reno 5 Pro has a 4350Mah battery with 65W fast charging support and Mi 10T pro has a 5000Mah battery with 33W fast charging.
Both will provide a similarly battery backup as Reno 5 pro has Amoled display which is more efficient than the IPS LCD one and has less refresh rate than Mi 10T pro so I think you will get an almost similar battery backup.
Winner — Oppo Reno 5 Pro(Due to better fast charging)
Oppo Reno 5 Pro — Rs35,990
Xiaomi Mi 10T pro — Rs39,999
Overall I think Oppo Reno 5 Pro is actually a really great deal for its price because you are getting an overall a great smartphone for a good price while for Xiaomi Mi 10T pro I can say it is also a really good device but in Rs40k you can add Rs2k more and get an Oneplus 8T which is a better choice than Mi 10T pro.