JKDFIGHTER has it correct, but I might add that if you don’t have Ajarn Chai's interests (I.E. the growth and betterment of Thai Boxing and the TBA) in mind, instead of your own by just wanting to get an Instructorship for the sake of having another piece of paper for your wall, then it may be a really hard test.
One point being that if your training includes actual ring experience then you will have more credibility. That said, I've had guys train and fight, and then want to test because they have their time in and think that its the next step, only to get to their Apprentice test and find out that their form either sucked or their ceremony looked like shit. (Ooooh, bad news!)
Now this wasn’t my fault because we worked on these things but then when I turn my back, they gloss over all of the stuff they were supposed to work on and then they wondered why they damn near got knocked out in their test.
Although as their instructor, I do feel responsible if my guy looks like shit because I work my ass off to only produce quality and will be embarrassed if they don’t perform top notch. The test is actually a reflection on me, and what I produce, and I’ve been known to do more pushups then my student at their own test. (My choice)
Also if you haven’t gone through your Students Level 1 & 2 tests under a recognized instructor like Sifu Francis or someone who has passed their Apprenticeship test then Ajarn Chai will scrutinize your form a little more. Also remember that the whole weekend is your test, how you act & how you train, all count.
Your Instructors should also be familiar with the testing too. Stupid mistakes that could have been resolved in everyday training will show at your test.
Here is a short checklist,
Does your Instructor demand that you show respect, both physically and verbally, while training?
If there are infractions on this issue, does your Instructor point this out and call you on it? (I teach a very fun class and we bullshit a lot, but if you got a problem with respect then expect to be a push-up king.)
"Yes Sir", "No Sir", verbalizing during knees ("Tang"), all of these little things will come out during the testing, and cause you some pain or a ride down easy street, until the pad rounds of course. (I.E. If you catch a break in your first round and just get winded because that’s what he wanted you to do, and then tells the second round pad-feeder to knock you out because he sees a major flaw that your Instructor should have corrected.)
Learning about the culture of Thailand is a prerequisite. Otherwise you should just be content at being a good Kickboxer and not even worry about testing in the TBA. Hey aint nothing wrong with that. But just to test because you want too, that isn’t what Chai is looking for.
Have you joined the TBA and have been a member in good standing prior to you writing your formal letter of request to the TBA office. I have actually been to a seminar were a major JKD Instructor showed up and wanted to test for Instructor at the seminar without any prior exposure to the process. Ajarn had never seen him before, so he found out where he lived and suggested that he come and train with me for a couple of years (because I was closer) and then come back and talk to him. He never did.