निस्·nis "out, forth, away" > nirvana "to blow out, extinguish; out of breath?"
नि·ni "down, back, in, into" < PIE *h₁én "in; down?"
My question is whether these words are from the same PIE root? And If they are cognates, how does the meaning shift from "in" to "out"?
PS: this is a post involving diachronic semantics, which I assume to be a subbranch of linguistics, so why did the close-voters vote "off-topic" option?