Avantika (अवन्तिका) is the Sanskrit name for the ancient city of Ujjain (Avanti) — one of the seven sacred cities of Hinduism. By extension, "princess of Ujjain."
Avantika Vandanapu (born 2004) is the Indian-American actress.
Avantika 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 Avantika reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.