What is possible depends very much on where your case would be heard (TVB or which court). I'm not sure what you are asking. If you plead guilty out of the gate, you won't get any consideration. The case is over. If you don't plead guilty, you can plead not guilty up until the due date (which is typical 15 days from the issuance).
If your case is heard in the TVB rather than a real court, there's no chance at all of a plea bargain or other negotiation. You're either found not guilty or guilty of the charge you were cited for. The only discretion the hearing officer has is to reduce the fine.