Soumya is from the Sanskrit सौम्य (Saumya — gentle, mild, moon-related, beautiful) — from Sanskrit soma (moon-god + sacred plant). Soumya is one of the Sanskrit feminine + unisex names — central to traditional Hindu Vedic heritage.
Soumya 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 Soumya reduce to 4, The Builder. This is a traditional interpretive system, not a factual claim about the name.