Lower Nubia wrote:I have a question, Is Tsar Nicholas a saint in every Orthodox Church, or just the Russian Orthodox Church?
That's not an simple question to answer since sainthood doesn't require a formal canonisation process in Orthodoxy. There can be a canonisation process, but there doesn't need to be.
It's further complicated by the fact that the canonisation process for the Romanovs was originally advanced by the Russian Orthodox Church Outside Russia [ROCOR] in the 1980s. At the time, ROCOR was officially considered schismatic by the rest of Orthodoxy, though their schism was often treated with sympathy since they broke away from Moscow during the Revolution in an attempt to keep the parishes outside Russia free from interference from Moscow when the national government was actively hostile to religion. Even now, with the schism healed and ROCOR considered an autonomous branch of the Moscow Patriarchate, the Romanovs have a different status within ROCOR (martyrs) and the main Moscow Patriarchate (passion bearers).
The short version is that since Nicholas II is officially recognised as a saint by a canonical branch of the Orthodox Church in good standing (acknowledging current jurisdictional tensions within Orthodoxy) then his status as a saint is recognised as valid. However, this places no obligation on other Orthodox Christians from other traditions to automatically include Nicholas in their own commemorations, though some certainly
choose to do so. It's a matter of choice.
Here's an example from a Greek church in the UK (though note that the church is named after the more usual Saint Nicholas rather than the Tsar!), and here's
the OCA's entry on the Tsar as saint.