Hello and welcome.

It's not a "coin", in the sense of being officially issued by a government somewhere for use as money or with a legal tender value. It's a medal of some kind. The question is, from who or where.
The cross at the bottom of the shield is definitely Serbian, which helps to narrow down the origin.
This Wikipedia article shows a coat of arms that looks identical to the one on this medal; the arms are the emblem of the Patriarchate of the Serbian Orthodox church.
I would assume it was issued as a religious souvenir from the main cathedral in Belgrade.
As with most "religious medals", narrowing down a date could be difficult. These medals could well have been sold over several decades, though I suspect it dates from after the collapse of communism in Yugoslavia.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis