As the others stated, it depends on the caveats or premises you use. The Central Powers preferred to get Russia out of the war first, even in OTL. They made multiple truly generous peace offers, that boiled down to near status quo ante. If such an offer is accepted, is the deciding question.
Scenario 1A: Russia accepts a generous peace offer: Some minor border corrections or shifts. Nothing drastic. As Lieven ably demonstrated in his works, as long as the Tsarist regime holds the loyalty of the elites, they would prevail. With a generous peace settlement and the likely story of being left alone and betrayed by their allies, it could be possible for them to retain their station. Nikolaus, in a rare moment of brilliance, abdicates and makes way for his brother, who institutes a system more in line to the A-H and German one. Democratic elements, with a strong executive under the nominal control of the Tsar. No civil war or anything more destabilizing. Any harmful or disturbing unrest is quelled either through concession or force.
Scenario 1B: Russia accepts a generous peace offer: This leads towards the elites making an ultimatum to the Tsar, they want a say and Nikolaus, as the bumbling idiot he was, answers with violence. Order breaks down and the regime faces a revolution. The Republic shortly contemplates to declare the peace treaty void and listen to the whispers from the Entente of the great spoils of victory, but sounder heads prevail. The Russian Republic then faces civil war with Tsarist loyalists and depending on the actions of the Entente and CP powers, one side or the other wins.
Scenario 2A: Russia rejects peace offers: Without some of the great successes of OTL and a quicker and worse crumbling of their front, the army is in a horrible state. The complete dissolution they suffered after the initial negotiations for Brest-Litovsk were abandoned by the Soviets would likely happen. Essentially, allowing Central Power forces to advance by train without a fight. In a follow-up, having lost massive prestige and standing among the elites and loyalists, Nikolaus is couped out. Considering how his brother did not have the aspirations or ambitions towards such an act, it would likely be a revolution to create a republic. Following the popular sentiment, they want to make peace and get a decent one, not generous, but significantly less than OTL Brest-Litovsk. Essentially a modified offer that was made to the Soviets OTL, on which Trotsky walked out.
Scenario 2B: Russia rejects peace offers: OTL happens earlier. Lenin is sent earlier and from there a similar line of events happens, but CP throws it support behind the White Forces after they got their peace. Considering Trotsky's move in OTL it would likely end with a treaty in line with Brest-Litovsk. With CP support and likely direct help, it is unlikely that the Soviets would carry the day.
PS: I know it is Tsar Nicholas.