Is this the correct way to ask which of two options is true?
あの CD は トルコご の ですか えいご の ですか？
("Is that CD in Turkish or English?")
in fact means
that is, "This CD, is it a CD of/about Turkish, or a CD of/about English?"
If you say
then you mean "This CD, is it in Turkish, or is it in English?"
Is correct, although
is more common for asking what language the CD is in. If the content is about Turkish/English themselves, then the former is more common.