Yes, immigrants tend to cluster together.
You can see the Gonura, the Ismaîn neighborhood of Verduria City, on this map (bottom center):
http://www.almeopedia.com/Ažimba
There are a fair number of Caizurans and Lácaturians, who don't have named neighborhoods, though they cluster in the poor neighborhoods. The Lácaturians are wanderers, criss-crossing the province doing seasonal work, entertainment, and light thievery.
There is a smaller and considerably more prosperous number of Kebreni and Érenati, mostly engaged as traders or scholars. Barakhinei come as laborers, theatrical performers, or Eleďi scholars.
There are people from almost any state in Eretald, but they are less conspicuous than these.
It's not rare to see elcari, either selling minerals or doing tunneling work. Flaids visit for trade, study, or tourism, but prefer not to settle there permanently.
A very modern phenomenon (i.e. in the last few decades) is to see natives of Téllinor, invariably children of the elite sent for education.
There is no embassy of Dhekhnam, and legally Dhekhnami ships are not even allowed to enter Verdurian ports. (The workaround is to trade through Kebri.) There are plenty of alarums about Gelálhists in Verduria, which should be take about as seriously as reports of Satanists in premodern Europe (i.e., not very).
It's not quite true to say that if you grew up in the city and speak fluent Mažtane, you'll be taken as native: people are conscious of family backgrounds and will remember if your parents are foreign. However, if your
parents spoke fluent Mažtane you can be accepted as native.