my phone was locked redmi note 4

You mean you have forgotten the lock screen password which is also used to encrypt your phone? In that case, the only way to gain access back to your phone is by factory resetting (wiping all data & settings) your phone.

To factory reset, you can boot to Mi Recovery to erase all the data and settings:
1. Power off your phone.
2. Press and hold the Volume Up + Power button to boot up your phone until you see the Mi logo.
3. In Mi-Recovery, select Wipe Data.

I don’t ‘know mi account , I’m not create how to power on my phone again again rebooting plsssss help me