Mini-Bio:
His real name was Niko Bellic he was living in Russia but after a maniac doctor kidnapped him, the doctor did experiments on him he changed his bones to metal, made him more intelligent, gave him incredible strength and accuracy
the maniac doctor tried to kill him but Niko escaped then he began to discover his powers and decided to call himself
"Nick Dwerz X"
Now he is living in Liberty City trying to find out why he did this to him.
He was born in Serbia. Proof Here:
"Niko was born in Serbia in Eastern Europe."
Source:
http://gta.wikia.com/Niko_Bellic
Scroll down to the beginning of "Early Life and Family". First Sentence.
nico is from russia. it was saying in the first part of the game that nico is from east europa ad he speaks russia and english so queshus13 is right about him