The US green card lottery program requires a person applying to specify a country of birth. The official site doesn't state anything about people who were born in one of the former republics of the USSR. Does a person who was born in one of the former republics (The Ukraine, Belarus, Moldova, Estonia just to name a few) counts towards the modern independent country that exists today, or toward Russia, as the successor of the USSR?
The instructions for the 2019 Diversity Immigrant Visa program (DV-2019) (pdf) are explicit about this:
- Country where you were born – Use the name of the country currently used for the place where you were born.
Note the phrase "currently used." This means, for example, that if you were born in Chisinau when it was part of the Soviet Union that you should enter "Moldova" as your country of birth.
When applying for the US visa, they explain they want the country in which the place you were born in is currently located.
So, assuming they have the same convention. in this case you should specify the relevant CIS republic.