This brand is eating Indian market share by a lot, because it offers a very good performance and features at a very reasonable price. Talking about their Mi Note 6 Pro, I purchased this phone few months back, and I have to say it's very good considering the price point.
Pros: -
1) Very smooth and good performance
2) Decent camera quality, lacks some details at night but overall it's good
3) Battery life is also very good
Cons: -
1) It gets a bit hot while charging and gaming because it has a glass black,
2) I personally don't like the back also because it is a very good fingerprint magnet, putting a case is good,
3) I am not a big fan of the OS system used in this phone, I like the one on the Samsung and google pixel.
You can consider your expectations and buy it accordingly, because no phone is perfect.