특별한 means "special, particular, unique, unusual, extraordinary"
인지 is composed of "이(다)+ㄴ지
ㄴ지 is an ending particle used for expressing vague question.
방세 조정이 가능한지 알고 싶습니다.
I want to know that the rent is negotiable.
그게 어떻게 가능한지 궁금해.
I was wondering how that was possible.