Redmi files a new design patent with single punch-hole display at the top-left corner. It might be the upcoming launch of the Redmi Note 9 series. Similarly, the Redmi Note 9 Pro & Redmi Note 9 will be equipped with a punch-hole design for placing the selfie camera. Whereas, other models are with regular notch display design. 
Redmi Note 9 series

As the patent design, Redmi Note 9 series will have the changes in display with punch-hole instead of notch display. Apart from that regualar placements like USB type-C port & speaker grille at the bottom. Likewise, volume keys, power button on the right. And 3.5mm audio jack, infrared sensor and secondray noise cansellation microphone is on top of the device. 

The other details are still unknown on Redmi Note 8 series. I’ll update when I got a new updates so, keep watch this space frequently.