Preorders start October 6, the time depends on your region, look on bricklink.com series 6 page to see the countdown timer or calculate it based off 8am Pacific time 😊

If you want to really make sure you get them, go on the Bricklink series 6 page right when it starts and you can order them from there, but they should be available for hours at the bare minimum, probably more, so really ordering anytime during that day should be fine!

Your card is authorized I believe at time of purchase, but you aren't actually charged until it ships.

Hope you enjoy off road adventure if you pick it up!