The composition of haplogroups for Croats is as follows: I1 5.5% (Germanic-Nordic), I2*/I2a 37% (South Slavic, Sardinian), I2b 1% (Germanic-Saxon), R1a 24% (Slavic, Kurgan, Aryan), R1b 8.5% (Celtic, Basque, Italic, Frisian, Saxon), G 2.5% (Caucasian, Georgian, Armenian), J2 6% (Greco-Roman, Anatolian, Mesopotamian), J*/J1 1% (Jewish, Arab), E1b1b 10% (Greek/Balkan, Middle Eastern, North African), T 0.5% (Egyptian, Middle Eastern), Q 1% (Hunnic, Central Asian), and N 0.5% (Uralic-Finnish, Siberian).
For Serbs, the composition of haplogroups (Y-DNA) is as follows: I1 8.5% (Germanic-Nordic), I2*/I2a 33% (South Slavic, Sardinian), I2b 0.5% (Germanic-Saxon), R1a 16% (Slavic, Kurgan, Aryan), R1b 8% (Celtic, Basque, Italic, Frisian, Saxon), G 2% (Caucasian, Georgian, Armenian), J2 8% (Greco-Roman, Anatolian, Mesopotamian), J*/J1 0.5% (Jewish, Arab), E1b1b 18% (Greek/Balkan, Middle Eastern, North African), T 1% (Egyptian, Middle Eastern), Q 1.5% (Hunnic, Central Asian), and N 2% (Uralic-Finnish, Siberian).
Sauce:
https://www.index.hr/vijesti/clanak/nacionalizmi-su-izmisljotina-geneticki-gledano-nema-velike-razlike-izmedju-hrvata-srba-i-bosnjaka/876729.aspx 
