Visa registration in Tunisia is handled only by the Tunisian Embassy in Moscow. Agencies do not deal with visas. You will either have to personally go to Moscow, or send documents by courier. Details of sending documents with a trustee can be clarified by phone of the Embassy: +7 (495) 691-28-58.

I remind you that when buying a package tour to Tunisia and the condition of arrival in the country by direct flight from Russia, on a similar flight, a visa to Tunisia is not required. The basis for entry is a tourist voucher issued by a tour operator.