Firemonkey to VCL - Best type of channel to use

Could you recommend the best type of channel to use. A FMX multi threaded/multi device. I am always a bit unsure when it comes to this. The mobile app will run on Win32/64, iOS, Mac and Android. It will communicate with a RemObjects VCL server. It must support both HTTP and HTTPS. The server will reside on an Azure VM.

you can use TROIndyHTTPChannel or TRONetHttpClientChannel (XE8+ only).
I’d recommend to test both of them and choose more appropriate for your case.

Can you tell me the difference? is one compatible with .NET and the other is not?

one is Indy based and second one is based on THTTPClient component (System.Net.HttpClient.pas)