Tanya is the Russian diminutive of Tatiana — from the Latin Tatianus, feminine of Tatius (an early Roman king). Country Music Hall of Fame (2023). Saint Tatiana — covered as separate name.
Tanya 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 Tanya reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.