Khushbu is from the Urdu-Persian khushbū (خوشبو — fragrance, pleasant scent). Khushbu Sundar (Nakhat Khan, born 1970) is a Tamil, Telugu, Malayalam, Kannada, and Hindi cinema actress, television host, producer, and politician — widely considered one of the leading South Indian actresses of the late 1980s through 2000s with over 200+ films across Indian languages. Widely venerated in Tamil Nadu — a temple to Khushbu was built in Trichy by devotees in 1999 (subsequently dismantled).
Khushbu 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 Khushbu reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.