Please help us to help you by reading and following the posting guidelines located in this thread: Please read before requesting assistance. The more information you give us the better we will be able to assist you. Thank you.
Environment details? (see Admin panel -> Dashboard -> Information)
This does not convey what version you are running since two versions are released simultaneously. (example that last release was 1.14.6 and 1.15.2).
For the Agent Ticket list columns you can go to Admin panel -> Settings -> Tickets and click on the Queues tab.
For the User Agent list you would currently need to alter the code manually.
I think that would be done here: /include/client/tickets.inc.php