Gargi (गार्गी) is from the Sanskrit gotra-name Garga. Gargi Vachaknavi (c. 7th c. BCE) was the Vedic philosopher — one of the few women to debate at King Janaka's philosophical assembly.
Featured in the Brihadaranyaka Upanishad.
Gargi does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Gargi reduce to 6, The Nurturer. This is a traditional interpretive system, not a factual claim about the name.