After the 90-day period of stay of a citizen of the Russian Federation in Ukraine, you can renew the registration at the place of stay at the most for 3 months. You can do this in the SGLFL (passport office at the place where you are going to register) or in OVIR.

Excess of a 3-month period of stay of a foreign citizen on the territory of Ukraine, according to part 1 of Art. 203 of the Code of Ukraine on Administrative Offenses (CoAAP) entails the imposition of a fine of 30 to 50 tax-free minimum incomes of citizens, which in monetary terms is 510-850 UAH

For violation of Part 2 of Art. 203 CCoAP, that is, non-compliance by aliens with the established registration procedure or the established period of stay in Ukraine, found at the border crossing points, comes with administrative responsibility in the form of a warning or a fine: from 30 to 50 tax-free minimum incomes of citizens, which in money terms is 510 -850 UAH