In the grouping, there some default group for customer reference, which customer cannot edit the ticket types in Grouping.
However, there's a way for the customer to edit the Ticket types in the Registration Form.
Here's the Grouping session which cannot edit ticket types.
Here's the Registration Form sessions that can edit ticket types.
1. Go to the lower part of the Registration setting, then you can see the "Tickets" part.
2. You can edit the ticket types in the "Ticket name" by changing the name, add or delete it.
3. Delete Ticket types: Click on right hand side "Trash" button.
Add New Ticket types: Click on the downside of a button.
4. Remember to click "Save Setting" after you edited it.