The complete Tafsir al-Tabari is voluminous. A verified complete set usually spans between depending on the print size. If you find a single PDF file claiming to contain the entire tafsir, it is likely an abridged (mukhtasar) version, not the full text.
To access a verified PDF of Taberi's tefsir, you can try the following sources: taberi tefsiri pdf verified
To sum up, follow these steps: