Russian citizens arriving in Tunisia not on a direct flight from Russia, a visa is required. The visa can be issued at the airport at the discretion of the border guard.

With the invitation of citizens of Tunisia you should apply to the Tunisian Embassy in Moscow, where you will be issued a visa to enter the country. It is better to do just this way. Either buy a package tour to Tunisia and visit the country on a tourist voucher, without the need for a visa.