You can register .ro domains and every Romanian extension (.com.ro, .info.ro, .org.ro, .store.ro and more), plus international ones such as .com, .net, .org, .e...
An availability result does not guarantee registration. Someone else may register the domain between your check and your application, or the extension’s registry may have reserved the name. Some extensions also have eligibility rules or additional requirements for particular names.
Check availability again and read the exact message shown during the order. If the issue continues, ask the provider to clarify, giving the domain name and error message without sharing passwords or card details. Do not assume registration is complete simply because the domain is in your basket or you have started payment: wait for registration confirmation.