Can I extend my one-year multiple entry Russian visa without leaving Russia?
Please take a note that multiple-entry visas are not extended. In order to stay in Russia for more you will need a new visa. You may apply for a new invitation for a visa while your visa is still valid. When your invitation letter is ready, you should leave Russia before your old visa expires and get a new one in any Russian Consulate abroad. Only the citizens of the countries listed below should get their visas in their native countries.