While major cities and well-traveled routes in Russia have good mobile coverage, connectivity in truly remote regions like parts of Siberia or the Far East can be very limited or non-existent.
In urban centers and along main highways, you can generally expect reliable service from Russia's major mobile operators such as MTS, MegaFon, Beeline, and Tele2. However, Russia is a vast country, and once you venture into sparsely populated areas, mountainous terrain, or deep wilderness, mobile infrastructure becomes scarce. An eSIM will automatically connect to the strongest available major network, but it cannot create coverage where no network towers exist. For specific remote destinations, it's always wise to consult local coverage maps from Russian providers if available, or prepare for periods without connectivity.