We already have several very similar questions on quora. So I'll just copy my previous answer: He was born (1856) and raised in Smiljan, Croatia, which back then was a part of the Austrian Empire, but still had a certain level of autonomy. read more
Nikola Tesla was a Serb born in the Croatian village of Smiljan. Nikola Tesla was born an ethnic Serb in the village Smiljan, Lika county, in the Austrian Empire (present day Croatia), on 10 July [O.S. 28 June] 1856. read more
"Nikola Tesla was born in 1856 in Smiljan in the province of Lika in what is today Croatia. At that time Croatia was the military frontier district of the Austro-Hungarian Empire and the area was sometimes referred to as the Krajina.. read more