It can vary for a number of different reasons, e.g. rated or non rated, base preference, your notice period, pilots declining agreed course dates at late notice etc etc. There is no 'typical' wait time in the hold pool. If you're non rated you are going to require a longer course and require more line training sectors than a rated pilot. If training capacity is an issue it might increase your wait time in the hold pool, it might not, depending on what the company's requirement is. Good luck. (I waited nearly a year for an interview then 2 months for the offer as a rated Airbus Captain. Others had offers immediately possibly due to base preference and notice period).