In Croatia, Bosca families are generally Croats (from Obrovac area ), very rarely Romanians.
Prevalence
About 10 people with faimily name Bosca live in Croatia today, in 9 households. There were 0 of them in the middle of the past century, and their number multiplied. They are only located in two Croatian cities and 5 other places, mostly in Gajine in Obrovac area (<10), Zagreb (<5), Srebreno in Dubrovnik area (<5), Hrvatski Leskovac (<5), and in Buzin (<5).