Getting banned from a Telegram group for bad behavior isn't very difficult. But sometimes group administrators want to reverse a ban. Telegram doesn't make it easy, and the tools to unban a user are well hidden in Telegram, and the path to find this tool is not intuitive. I wrote this for group admins who are having trouble finding out how to unban a user.
How to Unban a User Using the Windows Telegram Client:
If you are a group administrator, and you are using the Windows Telegram client, here are the steps.Open Telegram and go to your group.
Click on the group name. This will take you to the Group Info page.
Click on the 3 stacked dots (vertical dots) in the upper right corner.
Select "Manage Group"
This will open a page called "Edit Group". Now click on "Permissions."
From the Permissions page, click "Removed Users" to see a list of users who have been banned from the channel.
Now you can search for the user that want to unban, and then click "Delete" next to their name to remove them from this.
You can also add users to this ban list. Click "Remove User" at the bottom of the page, find the user and click on them.
How to Unban a User Using the Android Telegram Client
The process is a little different in the Android Telegram client.
Go to the group, and then tap on the group's photo.
Now tap on the Pen or Pencil icon to get to the "Edit" page.
On the Edit page, tap "Permissions".
On the Permissions page, tap "Removed Users."
On the Removed Users page, search for the person you want to unban.
Tap the 3 vertical dots next to their name and then tap, "Delete from this list."
Let me know in the comments if this worked for you! Good luck!