Mahal is from the Persian maḥall (محل — palace, place) borrowed from Arabic. Mumtaz Mahal (Arjumand Banu Begum, 1593-1631) was a Mughal empress and chief consort of Emperor Shah Jahan (1592-1666). Her regnal title Mumtaz Mahal (ممتاز محل — Exalted One of the Palace) was conferred by Shah Jahan after their 1612 marriage. The Taj Mahal means Crown of the Palace.
Mahal 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 Mahal reduce to 8, The Visionary. This is a traditional interpretive system, not a factual claim about the name.