Blocking unwanted SMS and calls is a good feature offered by Redmi mobiles. But sometime we want to unblock a number either we have blocked by mistake or we want to receive call from that number. Follow below steps to unblock a number from contacts.
1) Go to Phone book with dial pad open as below:
2) click thee "-" on the left bottom of screen and select "Blocklist".
3) It will open a screen with blocked "SMS" and "Calls" tabs. By default it will show "SMS". Click on "Calls".
4) Look for your number that you want to unblock and click on it.
5) On clicking, it will open a screen with detail call log of that number and "Unblock" button at the bottom.
6) Click "Unblock" to make that number active again.
Above steps are good with following versions:
Model: Redmi Note 4