This may be obvious, but is he planning to take the SAT or ACT in the spring of Junior year? The SAT is offered in January, March, May and June. Not sure about the ACT. One of my daughters did great on the SAT, the other one did good on the SAT but great on the ACT! She was so glad she took the ACT.
All colleges accept either test.
With my dd, the May SAT date was the day after junior prom

so she didn't want to take the SAT that day. So getting an early start in January or March can work out well. The deadline to register for the January test is usually in December. You can register online at collegeboard.com.
Collegeboard.com is a great resource. Lots of information about schools, finding matches for your student's stats, etc.
If he is really looking at upper tier schools, be aware that they may require SAT subject tests, called the SAT II. If so, a good time to take those SAT subject tests is May or June, at the end of the year you had the subject in school. Example, my dd took AP US History and took the SAT II in US History at the end of that year, since she was studying for the AP test anyway. You can take up to three tests at one sitting.
You can take the SAT multiple times if you need to improve your score...they now have "score choice" which means when you send your scores to the colleges, you can pick which ones to send..they used to send all of your scores automatically, although the colleges said they would consider only the highest.
Sometimes it helps once you have the test scores in hand, to know what schools you are aiming at. (You probably have an idea already from his PSAT scores.) Also, if he decides to apply early action, early decision, or apply for certain scholarship consideration, some of the fall test dates may be too late.
Doesn't Texas have some kind of automatic admission to the university for the top percentage of students? That might be something to look into as well.
Good luck!
