Answer:
The group that supported Czar Nicholas II during the Russian Civil War was the White Army.
Step-by-step explanation:
The White Army was the military arm of the White Movement, during the Russian Civil War from 1918 to 1921. It was formed by Russian counterrevolutionary nationalist, pro-zarist forces, which after the October Revolution fought against the Red Army. Most of its members had served in the army of Czar Nicholas II and sought the return of the monarchy in the Russian Empire.