In reality, Ukrainian males cannot leave the country now (18-60 years old should stay in the country, that's a military law).
Situation with Russians is a bit different. Russian males can leave the country, but that's a pure lottery because some of them (if they've been in the army - and it's a necessity for every male in Russia in most of the cases and what's worse - have some military-around profession or can just be useful to the army) will be turned back on the Russian border.
And even if Russian men not trying to get out of the country - it's still a lottery with a second wave of mobilization because army officers not looking if you have, say, 3 kids, by a law, you shouldn't be mobilized. No one cares and Russian men are being sent to Ukraine while their families are trying to get to the court with the claims, which is usually, surprise-surprise not getting anywhere.
