As the residence permit is over, you will need a document on the basis of which you will enter Tunisia. This is either a tourist voucher if you arrive in the country by a direct flight to a hotel paid by a tour operator, or an entry visa.

Since arriving from Turkey (this is not a country of citizenship), you need to obtain a visa at the Tunisian Embassy. When you enter Tunisia, you can apply for extension of residence permit.

For more information, see the page "Visa to Tunisia."