Just Building my knowledge base.
I have come across some applications/games that can run only on 64bit Devices and emulators and I was curious how we can also achieve that using B4A
You don't need to with B4A. As it is entirely Java based a B4A app can run on both 32 and 64 bit devices. The only circumstance that would restrict it to 64bits is if a library relied on a native code component that was compiled 64bit only.