So, in OTL the Russian Empire was huge. Poland, Ukraine, Belarus, Finland, Estonia, Lithuania, Latvia, Georgia, Armenia, Azerbaijan, Kazakhstan, Uzbekistan, Kyrgyzstan, Turkmenistan, Tajikistan, to say nothing of various minority groups, religious groups, and tribes living within those groups.
In the OTL, it all eventually fell apart and Russia was reduced to its current borders. Putting aside simply maintaining an Empire through brutality, to what extent can the Russian Empire be Russified by the present?
Can Russia get Ukraine and Belarus to have minimal independent identity and consider themselves Russian by the present, as France did with its minors groups? Can Russia achieve and maintain a majority in Central Asia beyond Northern Kazakhstan? Assimilate and flood with settlers the Baltic and Caucasus nations well enough to get Russian majorities? Can they Russify their Jewish or Muslim populations at all?
What policies would Tsarist Russia likely pursue, and how effective would they be? Provided Russification is seen as ideal, what policies should be followed?