The name could be of a few different etymologies. It could a German name, composed of the Old Germanic elements, is (ice) or isan (iron) and mari (famous).
Another possibility is that it is from Ismarus, a name of Thracian origins, but of uncertain meaning. It appears in Greek mythology several times as the name of a few Thracian characters. It is also the name of an ancient Thracian city and of a mountain
As of 2010, Ismar was the 91st most popular male name in Bosnia & Herzegovina.
I have read once that Ismar was chosen by Bosnian parents named Ismail und Maria, combining their first initial letters. Many other people liked the sound of it and that it can be used for people with different religious backgrounds. That is. the reason why it is so wide spread among Bosnians
That is interesting. Thanks for the extra info 🙂