Navigate to:
Click View All
Click Add
Click Create a Advanced List

1.Select the Objects 
In Constituent Information
User Base
User Phone
In Registration
Registration Event

2. Click Display Fields
3. Click Select Fields
Expand User Base
Expand User Phone
Expand Registrant 
Expand Registration
4. Select First Name/Last Name and Email in User Base
5. Select Phone Number in User Phone
6. Select Registration Id, and  Short Description in Registration
7. Click Filters
8. Click + ( Add Filter)
9. Select Registrant.Registration ID is Equal to (1234)

Note: You can obtain the Registration ID by going to
1. onMessage
2. Approval
3. Event Registration
4. Click Edit
5. In General Info there is a Registration Link, The last 4 digits are the Registration ID

If the Registration is Public, and the users are not logged in they will not display on the list as they were not logged in and there is no way to track this information. The best practice if you need them to display in this list is to make the Event Secured which requires them to be logged in to Register.