Russia Ukraine war, page-221840

Yes you are right civilians taking up arms and having a war inside a border after a coup is a civil war
Russia supported the breakaway republics in Ukraine sure. You didn't have Russian regular army units being involved and captured until 2022 when such units became involved. Yes individuals were involved as volunteers and no doubt advisors too and weapons and ammunition supplied.

Tell me where the civil war happened in Russia? What region broke away, how many civilians (civil war) took up arms and how many died? What battle ended the war?