Where does “नमो” come from?

नमो (Sanskrit) comes from Sanskrit नमस्, from Proto-Indo-European némos, from Proto-Indo-European nem- — to distribute; to give, to take.

Ancestry of “नमो”, step by step

Step	Language	Word	Meaning
1	Sanskrit	नमस्	bow, obeisance, reverential salutation,...
2	Proto-Indo-European	némos	sacrifice, worship; place of sacrifice, clearing
3	Proto-Indo-European	nem-	to distribute; to give, to take

नमो — Etymology, Origin & Word History | Etymology Explorer