Hello!

Kaçakçılardan ele geçirilen ve 8 yıldır Ankara Adliyesi’nin deposunda tutulan İncil, Etnografya Müzesi’nde kayıt altına alındı

Is it correct to translate it as: The gospel, which had been captured from the smugglers and for 8 years kept in Ankara´s court storehouse, was registered in the ethnographical museum.??

I am just not sure if translating kayıt altına alınmak as "being registered" is suitable in this context, because I´ve also seen it translated as "being tied down, chained".

"kayıt altına alınmak" is very formal expression only used in news, literal translation: "to be taken under registration". more clear translation: to be registered. if you want to use an informal simplier expression, just say "kaydedilmek" meaning "to be registered"