Katara is an American invented name created by Bryan Konietzko and Michael Dante DiMartino for Avatar: The Last Airbender (2005-2008) — inspired by Inuit naming traditions and possibly related to the Inuit/Yupik word qattaq ("waterbender" / "one who pours"). One of the most-acclaimed female animated leads of the 21st century — Avatar: The Last Airbender is on Time magazine's list of the 100 Best TV Shows of All Time and routinely tops critic-poll rankings of the greatest animated series ever made. Katara's character arc — from grieving daughter of a war martyr to powerful waterbending master and eventually wife of Aang — has been credited with influencing a generation of "strong female lead" animation in the West. Night Shyamalan's 2010 film (widely panned). Katara remains a character in animation studies; her healing-and-fighting hybrid character pattern preceded and influenced Steven Universe, The Owl House, and Korra.
Katara 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 Katara reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.