Orsk is the second largest city in Orenburg Oblast, Russia, located on the steppe about 100 kilometers southeast of the southern tip of the Ural …Orsk is the second largest city in Orenburg Oblast, Russia, located on the steppe about 100 kilometers southeast of the southern tip of the Ural Mountains. The city straddles the Ural River. Population: 239,800 ; 250,963 ; 270,711. It lies adjacent to the Kazakhstan–Russia border.