When does the 90-day reporting period start after renewing a Non-O visa in Thailand?

The countdown for the 90-day reporting generally starts from the date of entry into Thailand, which in your case would be 29 November. However, some community members suggest checking any slips provided by immigration or confirming directly with immigration, as the date could also be counted from when you last interacted with them, which is 6 December in your case. To avoid potential fines, it's recommended to check or report earlier if unsure.