Whois is a service that allows insight into basic domain data such as who owns the domain, nameservers, when the domain was registered and when it expires.
It is possible to check this for each domain.
For RS domains you can check here.
For international domains you can here.
Whois protection means hiding ownership data, ie who is the owner. It is free for international domains. RS domains are charged 500 dinars per year.
Regarding the RS domain, no data is displayed for natural persons regardless of whether they have paid or not, while for legal persons it is shown which company owns the domain.