It's concentrated in northern Serbia.
Well my data for Voyvodina( North Serbia) say : I2a 29,73% , E1b1b1 16,22% , R1a1a 15,14% , J2 11,35% , R1b1b2 10,29% ,
I1 5,24% , G 3,24% , N 2,7% , Q1b 1,08% , others 4,86%
Voyvodina has 2.031.992 inhabitants and whole Serbia (with Voyvodina , and without Kosovo ) 7.498.001 , so it is imposible that all of N1c1 is in Voyvodina .
Also until 1918. Voyvodina was part of Hungary ( but with most of population settled from lands where Serbs live , Turks force out all Hungarians and settled Serbs , later when Austro Hungary took these aerias they settled more Serbs , Germans , Romanians , Hungarians , Slovaks , Czechs , Rusini,...) , and Hungary has less N1c( 1%) then Serbia( 2%).
Thanks for answering