Look for scans uploaded by academic users or libraries. Check the "Metadata" tab on the left. If it lists "Publisher: Hisar" and "Language: Turkish (Ottoman)", it is verified.
For Turkish readers wanting the translation: taberi tefsiri pdf verified
Some complete sets include a separate Mujallad al-Faharis (Index Volume). Use the PDF’s search function (Ctrl+F) sparingly, because scanned images are not OCR’d. Instead, use the index to locate verses. The Ultimate Guide to Finding a Verified Taberi