Kondratuk > closer transliteration probably KondraTIUK.

As per Ellis Island, surname found in what was Vohlyn Region > today broken down into Vohlyn and Rivne Oblasts/Regions.

From late 18th century to 1921 this was Vohlynskaya Guberniya/Region > Russia. From 1921 to 1938 it came under Reconstituted Poland's domain and called Wolynskie Wojiwodstwo/Region > Poland. Post WW2 it came under Soviet Union (SSR Ukraine) until 1991, when it became part of independent Ukraine.

KONDRAT is an ancient Rusyn (not Russian, but Kievan Rus) given name meaning SQUARE. IUK suffix common to Vohlyn Region (today Vohlynska & Rivnenska Oblasts) Ukrainian surnames. Means BELONGING TO.