The phrase "namiya mia siterip" appears to be a phonetic interpretation of lyrics from the popular Newari (Nepal Bhasa) song "Namaste Mia"
Conclusion
: The lyrics often revolve around "Namaste Mia" (a respectful greeting to a young girl/woman in Newari culture). The term is likely a phonetic misspelling of "Sita Rep"
Literature: There are mentions of a Namiya Mia Trio, which is referenced as a collection of books.