Essentially, how can a country deal with the religious differences of immigrants, especially if they come into conflict with the major religion(s) of the host country.
As one example, is America (which is 82% Christian) effectively work out differences between Christians and Muslims, whom a number of Americans blame for all of terrorism...even though the vast majority of Muslims are peaceful and there are some Christian terrorist organizations (like the KKK). The point here is, Christianity and Islam are at odds in America, at least for the moment, can the government and society as a whole find ways to diffuse those problems and maintain peace between these two groups?
Other examples include France's recent decision to ban burqas (the veils that some Muslim women wear), how Ireland has dealt and continues to deal with the Protestant/Catholic divide (which has often been very violent and full of terrorism itself), Communist countries and how they deal with religion in their respective countries when Communism is by its very nature anti-religion, etc.
For the question you ask, mostly it is talking about how a government of one country deals with the differences between religions of the native peoples vs. that of immigrants.