If he graduated from the military department and is a reserve officer, he is currently a student

As a general rule, reserve officers are subject to conscription during general mobilization. However, there are specific cases clearly provided by law when reserve officers will not be called up. These grounds are determined by Article 23 of the Law of Ukraine "On Mobilization Training and Mobilization." According to it, conscription for military service during mobilization is also not subject to a special period

recipients of professional (vocational and technical), professional pre-higher and higher education, trainee assistants, post-graduate students and doctoral students studying full-time or dual forms of education.

So, while you are a full-time student, you are granted a deferment from the draft, and therefore you cannot be drafted at this time.