Like the alleged genocides in Luhansk and Donetsk - if the case is clear, why noone including Russia submitted it to international institutions? For example Rus

Like the alleged genocides in Luhansk and Donetsk - if the case is clear, why noone including Russia submitted it to international institutions? For example Russia was a member of Council of Europe together with Ukraine so they could have put all this stuff to the human rights court in Strasbourg.