how can I get a full scholarship to MIT
Have an EFC of $0
MIT provides need-based aid only, so yes a student receiving a full ride would have to have a very low EFC…as calculated by MIT using the information on a student’s CSS Profile.
Even then, MIT FA packages often include a student contribution/earning thru work (expected in summers and/or during the school year). Some FA packages also include Federal Direct Student Loans (if you are a domestic student).
Consider ROTC