Is it possible? Yes, as long as you currently active, have some time with an INF unit, and meet the requirements. This is not a school you will easily get.
As for SOTIC, you will not attend SOTIC unless you fall under USASOC. Even then, competition is very stiff.
In all honesty, the likelyhood of you attending either one of these schools at this time is zero.
I would focus on what direction you want to go, do you want to be regular INF? Abn INF? Do you want a chance to pass RIP or SFAS? Focus on that, worry about the schools later.
Thanks, though my motive for asking was mis-understood. I asked because of the fact that I have just recently found interest in the possibility of sniper training. Previous to that I already was going to the local DEP functions at the recruiters with intent to sign an Inf contract with Abn in it. Sadly I'm not of age to sign, but otherwise I am doing all I can to prepare for an Army career. Thanks for clarifying that one small detail though.
Unless it's changed you can join at 17 with your parents permission. I joined up at 17 that way. Funny thing was, I grew another 4 inches my first year in. Supply sergeant hated to see me coming he he.
Think of it as more time to prepare .. when you are old enough, after starting to train and prepare yourself so early, you'll have a very good advantage. Good luck, never quit.