People I asked hadn't heard of the company but then again Brazil is huge so might not mean anything.
I found an article about Nova Atlantida saying that a Spanish developer had taken over that development from Grupo JR: on their website they do say that they are doing the development so seems both companies lay claim to the same one...
Afirma Grupo Inmobiliario / Site search So, one of them hasn't updated their website in a while or is fibbing...
First thing I'd do if I were you is take random pieces of information from a developers website and google them; (development names, names of team members, any claims to fame really - awards, offices, etc).
See if anything stands out.
If everything on their website checks out and you really like the project and are considering investing then start the legal due diligence process.