Ratna (रत्न) is the Sanskrit word for "jewel" or "gemstone" — used widely across Hindu-influenced cultures including Indonesia and India. The Triratna ("Three Jewels") are the concepts of Buddhism.
Ratna is widely used in Indonesia and India.
Ratna 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 Ratna reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.