There are no entrance requirements other than to pay the nominal entry fee (which gets you a t-shirt, gets your results on the TSC web site, etc.) and sign whatever waiver form(s).
The next International TSC is April 19, 2014, according to the web site.
Any SFG is authorized to host a TSC, so if there isn't one in your area, contact an instructor and suggest it!
I agree it would be great if a list of past locations, and/or a list of planned locations for the next meet could be viewed on the TSC web site. How about using the Contact Us link on the site's main menu and making that suggestion yourself?
-S-