Cika wannan jumla: A matakin matasa matasa, Kulboka ya wakilci Lithuania a matakin kasa da kasa a lokuta da dama, ciki har da 2014 FIBA Turai Under-16 Championship da 2015 FIBA Turai Under-18 Championship. Ya zira kwallaye 15.7 a wasan a gasar 2016 FIBA Turai Under-18 Championship, a kan hanyar zuwa lambar azurfa. Ya kuma yi gasa ga Lithuania a cikin
2017 FIBA Under-19 Kwando Gasar cin Kofin Duniya, yana da matsakaicin maki 13.7 a kowace gasa. A ranar 26 ga Fabrairun 2018, Kulboka ya fara aiki a matsayin memba na babbar kungiyar 'yan wasan kasar Lithuania, ta hanyar zira kwallaye tara, ya kama kwallaye biyar kuma ya ba da taimako biyu, kuma ya taimaka wajen murkushe kungiyar' yan wasan Kosovo, da ci 106<unk>50, a lokacin gasar cin kofin kwallon kwando ta FIBA ta 2019.