You should submit the results for your event within 7 days of its conclusion. In Paris Brest Paris years, brevet results in June are due immediately after the event for those events that might qualify one or more of your riders for PBP.
Even if your event had no finishers or was cancelled, you must submit a report.
Note that, first time RBAs on provisional status must send their brevet cards to the Brevet Coordinator immediately after submitting results of their first event.