Of course Asia Dude.........
Both, part of Russia's provinces are in Europe and some are in Asia
Both, part of Russia's provinces are in Europe and some are in Asia. See the following Wiki article.
It is technically considered Eurasia for the reason of in lying in both Asia and Europe. Though the most populated area is in Europe that doesn't make much of a difference. It is just both. Some times Europe and Asia are just considered one big 'Super Continent' for political reasons.
Geographically, Russia started out European and expanded into Asia, not the other way about. If someone says Russia has become Asian by acquiring more land in Asia than its initial size, then it logically follows that France and Belgium were at one point African countries. I've never heard such a claim.
Also, Russia has more territory in Asia but less population. Most of Russia's 140 million people live west of the Urals.