... of Russia's regions
Как вариант.

Russia’s regions -or- the regions of Russia

of the Russian regions - неверно?
а " composite portrait"?

Russian regions is certainly not incorrect, but it could refer to Russian regions in another country or city.

I have no idea what Собирательный образ means.

I can't imagine Russian regions in another country 🤔

like generalized portrait

collective character?
Individual and collective character of cities - https://www.britannica.com/place/United-States/Individual-and-collective-character-of-cities

Собирательный образ - это выдуманный/искусственный образ, объединяющий в себе самые главные (и, вообще говоря, повторяющиеся/общие) черты реальных объектов

I can't imagine Russian regions in another country

Like Chinatowns or Brighton Beach

But they aren't Russian regions😁

Maybe not Russian, but in Germany, for example, there were Polish regions that had two names - one in German and one in Polish.

districts, not regions

Chinatowns and Brighton Beach are regions/zones/sections/divisions of cities.

In other words, Russian regions is ambiguous, but the regions of Russia and Russia’s regions leave no doubt that they’re in Russia.

ok, got it

Thank you guys! So much useful information for me.

Could I write something like Russian Federation's regions. Will it be also correct?

The regions of the RF would sound better

thx 👍