What is the process to obtain a multi re-entry permit in Thailand and how long does it take?

To obtain a multi re-entry permit in Thailand, you can go to the main immigration office in Bangkok or any immigration office, including those at airports which are open 24/7. It's advised to arrive early and bring your passport, a copy of the first passport page, and the necessary fee (including a 200 baht service charge at Suvarnabhumi Airport). The process at airports is generally quick, averaging around 10-20 minutes, depending on the time of day and the number of people waiting. For re-entry, ensure that you use the re-entry permit number on the TM6 form.