There is no objection to mingling between males and females in schools, universities or other institutions provided:

• It does not transgress the boundaries of decorum and Islamic teachings.

• Females must dress decently; their clothes should not cling to the body nor be transparent and they should cover the body. Females must also lower their gaze and stay away from being alone with a member of the opposite sex, whatever the reasons.

• Both sexes are required to be mindful of Allah with regards to their eyesight (lowering their gaze), hearing and feelings. Allah said: Tell the believing men to reduce [some] of their vision and guard their private parts.
That is purer for them. Indeed, Allah is acquainted with what they do.
[Qur'an 24:30]

The Ruling

Mingling between the sexes is prohibited if they do not adhere to Islamic teachings and decorum and if it incites desire and leads to prohibitions.