"Mereka tidak resmi."
Terjemahan:They are not official.
Legal is not the same than official in English.
Legal: allowed by the law /connected with the law: (Contoh: legal advice, legal obligation, legal status, legal right, legal action, the legal representatives (=lawyers)
Is alcohol legal in your country?
relating to a position of responsibility:
He visited China in his official capacity as America's trade representative.
the official photos of the president's tour of India T he Queen will attend the official opening of the theatre in June.
There is to be an official inquiry into the incident.
If a piece of information is official, it has been announced publicly with authority.
Resmi = official.
Legal = legal, or sah (depending the context)