Which aspects of Russian society were most in need of reform at the outset the reign of Nicholas II?
The most pressing problem when Tsar Nicholas II came to power in 1894 was how Russia would respond to the changes that came about because of industrialization. Russia was industrializing (albeit slowly) during this time and these changes were causing social disruption.
Most significantly, the new factories brought terrible working conditions to Russian workers. These were worse than those of most other contemporary countries. These conditions, coupled with low pay, long hours, the fact that labor unions were illegal, and other such things meant that the urban workers were primed to rebel.
It is also worth noting that the agricultural sector was not much better off. Peasants farmed small plots inefficiently and some large landowners held large amounts of land, thus making the smaller peasants unhappy.
This means that there was inequality and unhappiness among peasants and workers -- not a good situation, and one that needed to be reformed.