.UA domain registrations generally require a matching trademark right, such as a Ukraine trademark or a WIPO/Madrid trademark covering Ukraine. The trademark name should match the domain name, and this applies to both company and individual registrants.
.com.ua is a different zone and normally does not require the same matching trademark document, so it may be easier if you do not have a matching trademark.
Better to confirm this before paying for the domain, especially if you are buying it from another owner.