It is a very common and stupid bug by XIOMI MI/Redmi phones.
It can solved easily but u need to have more patience ?
Even if you connect the charger, you will not be able to see any sign of charging and continues blink (kind of boot loop).
I am sure this should be the problem for you (not only you, more than a millions)
• Connect the phone with a charger, you may or may not see any sign of charging
• Wait for at least 15 minutes and max of 45 minutes until you notice some sign of charging
• Never disconnect the charger even for a single second while doing it
• After a good amount time you get any of the below,
• Phone booted without any issue :-)
• If not use Power + Vol Up button to boot into recovery mode wipe all,
• I not Vol + Down to fast boot. Keep charging until u see any sign of charging.
• Try with another charger if it did not work
Let me know whatever result u get, I will give u the good solution, but do not forget to reply.
Cheers,
NallasivanG
https://twitter.com/NallasivanG