Russia was a large empire at the time of your ancestor's birth. W
From what document did you collect his precise place of birth?
Do you know language spoken by your ancestor? Did he considered himself to be Russian, Ruthenian or Ukrainian?
Roman SCHETKA - U.S. Social Security Death Index
Birth: 2 Dec 1894 State Where Number was Issued: Pennsylvania Death: Sep 1965
You might want to request his SS-5Form as it should have his place of birth and parents names. You might also want to check the church he attended, got married in and had the children baptised in. If he was naturalized citizen than his intent and petition will have his place of birth.