Where does “वृत्तान्त” come from?

वृत्तान्त (Sanskrit) comes from Sanskrit वृत्त, from Sanskrit वृत्, from Sanskrit अन, from Sanskrit अन्, from Proto-Indo-European h₂enh₁‑ — to breathe.

Ancestry of “वृत्तान्त”, step by step

वृत्तान्त traces back through two separate lines of ancestry.

via Sanskrit वृत्त

Step	Language	Word	Meaning
1	Sanskrit	वृत्त	Turned, set in motion; Round, rounded, circular;...
2	Sanskrit	वृत्	to turn, to rotate
3	Sanskrit	अन	breath, respiration
4	Sanskrit	अन्	to breathe
5	Proto-Indo-European	h₂enh₁‑	to breathe

via Sanskrit अन्त

Step	Language	Word	Meaning
1	Sanskrit	अन्त	near; last; handsome, lovely
2	Proto-Indo-European	h₂ént-	end, limit, forehead

Every word from Proto-Indo-European h₂enh₁‑ →Every word from Sanskrit अन् →Every word from Sanskrit अन →