You must unlock the bootloader to install another recovery. Waiting time to unlock this device be in range 72-720 hours and no way to miss this step.
But don't worry, we don't have official TWRP for this device.
Depends. I not wait. I unlock fist Redmi 6 and after that Redmi Note 6 pro after phones arived to me. Redmi 6 i unlock month ago and 2 days ago arrived to me redmi note 6 pro and after 2 minutes i unlock btl.
I have ask for You. Can You see on aliexpress or gearbest a same silicone case transparent black same like on box from Xiaomi case with Redmi Note 6 Pro? Its awesone good case. I want buy next for another phones.
Previously had my bootloader unlocked no problem, same device and I relocked, tried again to unlock with the same binded account and I have to wait 366 hours, I have previously unlocked bootloaders with Xiaomi before and usually free to unlock/lock without having to wait again. Can someone advise what's going on here. Many thanks.