Janice is the 20th-century English elaboration of Jane — from the Hebrew Yochanan ("God is gracious"). MY... GOD!" was named to TV Guide's list of the 100 greatest TV catchphrases.
Janice 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 Janice reduce to 6, The Nurturer. This is a traditional interpretive system, not a factual claim about the name.