From the pms i've received i should add that most basic questions can be answered on the Zagreb medical school website:
Medical Studies in English
In the cases where that doesn't help, I'm here. But note i'm not omniscient, you mite have 2 tell me about urself, so that I help u. Kinda depends on the question u ask eg. prerequisites depend on where ur from.
Also apply directly to the school. Never use agents. They offer no advantage and cost alot of money.