Answer
Yes, there is a Russian-speaking community in Uruguay: it is not very large, but it is not uncommon either. In Montevideo, you can find people who help newcomers with everyday and immigration matters, guide them through their first steps and share contacts.
This kind of support is especially useful in the first weeks, when housing, connectivity, documents, medical care and an understanding of the area are all needed at once. Russian-language chats and acquaintances help you find a specialist or ask a question without a language barrier.
But it is not in your interest to remain entirely within the diaspora. For a stable life, you still need Spanish, local contacts, neighbors, work, study, sports or other social circles. The best option is to use the community as a starting point while also integrating into the local environment.