RN is an identity document (ID) of the .lt domain holder. The domain holder’s ID (RN number) is required when a holder of the .lt domain wants to perform the domain trade procedure (change the registrant).
The .lt domain holder’s ID is provided in your domains.lt account: choose the menu item “Initiate domain trade”.
More information on the domain trade in .lt domain is available here: https://www.domreg.lt/en/faq/for-domain-registrants/how-to-trade-your-rights-to-domain-to-another-person/
