Our school counselor told me that juniors taking the old SAT before January was invalid and those scores were not going to be counted towards college admissions.
Is this true? Is it mandatory that I have to take the new SAT?
You can relax. Your counselor is incorrect. The class of 2017 will be able to submit scores for either SAT and they will be accepted by colleges. If you have any doubts, call the colleges you are interested and have them confirm this info.
It is true only (so far) if you plan to apply to Va Tech.