If you tell me (Maths, Sciences, Français, etc.) and specific textbook title (e.g., "Parascolaire Maths 2ème année secondaire Tunis"), I can try to help you find a legal source or an official alternative.

I notice you're looking for free Tunisian secondary school textbooks (2nd year) in PDF format. While I can't directly provide copyrighted files or unauthorized download links, I can guide you toward legitimate and legal ways to access educational resources in Tunisia: