I know someone who went to touro in the last year or so… so, according to them:
Undergraduate courses at touro college flatbush are separate. That is if you go through the regular LAS program. Mondays, WED, SUN nights are for men. Tuesday, THURS, and Sunday morning and afternoon are all for women. They dont let students of the wrong gender (depending on the night) past security. The security guard goes around and kicks people out, the library staff make sure you leave ect.
You can opt to take a class in the SCAS program, which is their program so they can write that they dont descriminate on the bases of gender ect. Any person can be a part of the program, like any other school. These classes are in the morning MON-FRI. If you go through the LAS (FRUM) program, you do NOT have to take classes here. Some do because of convenience ect.
Touro Graduate schools- those have a mechitza.