Is it possible to redo my contract again to become a Reserve officer? Is it possible to switch branches?

SPC Chan,
A bit confused, where are you waiting to get shipped to? I assume you have completed basic and AIT or is that where you are waiting to go? Two primary ways to become USAR officer, OCS or ROTC. You already have a Masters so ROTC is out unless you were going for your Doctorate, then you could do that, or you would be looking at OCS. You would have to be recommended for that by your chain of command, which if you are not in a unit yet, then you really don't have one. You might look at one other option, that is a direct commission, but that mainly depends on what specialties you can offer the Army (Doctor, Lawyer, PA, etc)

Every branch has an Intel branch. Your degree major doesn't determine what branch you get into in any of the services are. You can still go to OCS or with your current MS you could direct commission to a cyber branch in the NG or USAR. I wouldn't waste your time trying to switch branches to the AF on your current contract.

I would strongly recommend you find your nearest Army Reserve Career Counselor. More specifically you want to find an AMEDD Recruiter. AMEDD is a unique population that this type of recruiter can best answer your questions and assist with your career goals. It seems like Direct Commission may be a viable option, however, an AMEDD recruiter can help you identify what AOCs you may be interested in and there are a lot of paperwork and processes involved so you have to stay on it. Again, as an Officer, a lot is expected of you to do your own research and be proactive in your career, especially in the Reserves nothing will do itself for you. Good luck.