'Ambit' is a small word with useful meaning, I like it, and I was surprised I was not already familiar with it.
2) a: The space surrounding a house, a castle, or a town; precincts. b: The bounds or limits of a place or district.
In searching for quotes I found 17,687 hits in one news archive, which is a huge number, but all the ones I could reasonably check there were part of the names of companies: Ambit Energy, Ambit Holdings Pvt. Ltd, Ambit Biosciences Inc., Ambit Alpha Fund, Ambit Bridge Loan Fund, Ambit Biosciences, Ambit Treasury Management, Ambit International, Ambit Microsystems, . . . .
I still hear it occasionally, although I suspect that most people tend to use it with broadly the same meaning as "remit", with which it may well be being confused. Thinking about it, I suspect I have only heard it recently in the phrase "outside his ambit", where "remit" is quite probably more appropriate.