Well it is not as strict as what the United States is doing that most of their STOs or even regular ICOs are only allowed to be sold in a private sale. In Europe crypto regulation is almost non-existent which means if its not yet illegal its legal. So participating in any ICO sales done locally in your European country won't put you under any radar. But just to make sure look for any specific regulation happening in your country as from what I know countries like Italy and Germany are moving faster when it comes to their own regulation for crypto.
thank you very much for your answer.
as far as I understand, private placements for ICO especially are related to professional investors/qualified investors etc.