First things first, there are no 'denominations' within Orthodoxy. The Orthodox believe in one, holy, catholic, and apostolic Church (as professed by the Nicene Creed), and they believe that the Orthodox Church is it. Therefore it would be inappropriate to speak of a doctrinal position of the Russian Orthodox that is not also true of other Orthodox. While they are under different jurisdictions, they are the same Church and thus share the same beliefs. With that said, there are at times differences in emphasis between jurisdictions, and they don't always see eye to eye. The difference is that they generally do not split from one another and form separate 'denominations' as in Protestantism. They remain in the Orthodox Church and continue to seek reconciliation. Orthodox recognize that reconciliation may take years, perhaps centuries. So they don't rush these sorts of things. I should also mention that it is very precarious to attempt to speak on behalf of all of Orthodoxy when it comes to this issue, but I will do my best to represent what is the most prevalent view within the Church, with the caveat that not all Orthodox may agree (and that is OK).
With that being said, the answer to this question depends on whether you are talking about the Russian Orthodox Church Outside Russia (ROCOR) or the Russian Orthodox Church itself. There shouldn't really be any distinction since as of 2007 the ROCOR is now in communion with all of mainstream Orthodoxy because of its incorporation into the Moscow Patriarchate. However, ROCOR is still self-governing, and its clergy and members are notoriously hyper-conservative and separatist. Regardless of this, they do not represent all of Orthodoxy if they claim that those who are not chrismated in the Orthodox Church are damned.
Fr. Damick offers a short explanation:
The final boundaries of the Church are known only to God himself, but
outside the historical context of the Church—that is, the Orthodox
Church—the nature of the connection of any human being to the Church
(whether a believer in Christ or not) is unknown to us. Throughout
Church history, various groups have broken from the Church, a tragic
reality which does not divide the Church but rather divides believers
from the Church. The final status of Christians in such communities is
dependent on God’s mercy and grace, which is also true for those with
membership in the Church in this life.
In this life, however, to be an Orthodox Christian means belonging to
the Orthodox Church. It is not something one can do alone or as part
of a separate group. Orthodox Christians believe that other Christian
or even non-Christian groups may manifest varying degrees of the truth
of the Gospel but that the fullness of the Christian faith is found
only in Orthodoxy.
This is in stark contrast to Protestantism which considers the Church to be spiritual (and thus no one group can claim to be the Church). Orthodoxy, on the other hand, insists that it is "the fullness of The Church." According to Timothy Copple,
When the Orthodox Church says that it is "The Church," they are making
no pronouncement upon the salvation of anyone inside or outside
membership in Orthodoxy. This may be hard for Protestants to grasp
since being saved and being part of The Church is practically
synonymous when linked to the spiritual Church. The knowledge that not
everyone, let's say, in the Baptist Churches will be saved only serves
to reinforce the fact that the Baptist Church cannot say it is "The
Church". Yet, they also firmly believe that there are many who will be
saved, so neither can one say that any other group is "The Church."
While Orthodoxy does believe that ultimately to be saved means being
in the Church and those outside the Church will not be saved, that
issue is not fully decided until judgment day. Because salvation is
not looked at within Orthodoxy as either an in or out position but a
journey into God. We readily recognize that anyone inside or outside
the Church at any particular point in time can be in the currents of
salvation or not participating in it. Thus, there is no ability to
point to any one person either inside or outside the visible Church
and say they are saved or not saved. Whether any one particular person
is going to make it to heaven we leave in God's hands. We cannot know
the heart of the person, much less the disposition of God towards a
particular individual short of God revealing that to us.
Orthodoxy also does not say that the visible governing body of
hierarchs and the organizations that are called the Orthodox Church
are in and of themselves "The Church". This is an understandable
confusion because what is generally labeled as synonymous with the
visible church in Protestant circles, if they have any concept of
that, is the governing body, the denomination or local church. It is
by becoming a member of such-and-such group that one attaches
themselves with like-minded Christians and is called "a church" in a
visible aspect. Therefore, when a group says it is "The Church",
Protestants will tend to think that the group is claiming that their
fellowship, their organization, their denomination or local church
body is a one-to-one equivalent to all those names written down in the
Book of Life.
Given what we just discussed above, it should be evident that this is
not the case within Orthodoxy.
There are a lot of underlying worldview issues in this question that Copple addresses if you'd like to learn more (especially the tendency to separate the spiritual from its physical manifestation, a common dualistic worldview inherent in Modernity).
In conclusion, the general attitude of all Orthodox can be summarized by saying, "We know where the Orthodox Church is, but we do not know where it is not."
