Grenada takes your application file and makes a copy paste of it with the DOJ (U.S.) due to the E2 treaty they have, because of this many avoid Grenada. Funny enough, since the Ukraine war, we did so many Russian files for Grenada up until March 2023, when the PM banned them as the rest.Grenada and Antigua, around 6 months for both (Grenada a bit faster).
Theres a few youtube videos that explain how it works way batter than I could ever do.
Antigua is by far the best option in the 5 CBI countries available, it is relatively new, more transparent process when compared to the rest, and hasn't attracted the shmucks and the sketchiest people on this planet like St Kitts, Dominica etc.
However, this 6 months timeline is old news. Nowadays it is taking up to a year to get Citizenship certificates and Passports delivered. EU commission is heavily lobbying against these programs so the new timeframes can be up to a year. Whoever is telling you 6 months is pulling your leg to get the deposit faster.
The last file we got approved for U.S. clients took about 13 months start to finish. If you are lucky, you can get it within 9 months, but not less.
Also by the way, soon prices will dramatically increase. St Kitts upped their pricing to $250,000 donation only without any Govt./professional fees. Other 4 CBI Caribbean countries probably will follow suit soon.