✔ 最佳答案
There are so many dialects in India, they all have different sayings to just one thing!
If it's just simple Hindi (not Sikh, not Punjab, no religious purposes), then it's:
Namaste (naa-maa-s-taa) or
Namaskar (naa-maa-s-kar)
'Nam nam' is most likely: 1) a shorten form for kids 2) a play on words