-냐 마냐 pairs a verb with its own negation to mean "whether X or not," and it marks a question still hanging in the balance: 3만원 지폐권이 나오냐 마냐 하는데, 이 코너를 하냐 마냐 할 때, 그럼 부통령 하냐 마냐지. It usually sits in front of 하다, or takes a particle so the whole undecided question becomes the topic: 나머지 산토끼를 갖고 오냐 마냐의 문제인데. The plainer -는지 안 -는지 says the same thing more neutrally; -냐 마냐 is punchier and belongs to speech. These lines run from variety chat to political commentary.