To add the field in the Incident Console you have to add the field in the Incident "Fields Sets" in the Incident custom object.
The Incident object have Field Sets like:
Console - Client Details, Console - Date and Time, Console - Incident Details, Console - Service and CI, Console - Status and Priority Etc.
To access the Incident field sets:
>Go to Setup | Create | Objects | Incident Object
>Scroll down to the fields sets select 'edit' for the field set in which you want to add the field.
>To add new fields to the list of incidents in the Incident Console Tab, Drag and Drop the fields to the Column Headers field
>Verify the desired field appear in the Incident Console.
My question is not how to update field sets, my question is how to make Fields available to Field Sets