A lot of people ask me about RAM requirment of their android phone. But actually it depends upon user to users. now people use their phone for various purposes so, the ram requirement also varies from users. For casual use 4GB ram is enough, specially in case of stock android os. For other custom operating system 4GB is also sufficient. But if you are using your phone for heavy gaming then you should go with 6GB of ram varient, because game required a lot of ram and you can play smoothly. The next type of users, who prefer phone for heavy multitasking or video editing, they also need 6GB of ram for better experience and smooth experience. A lot of ram is consumed during multitasking so, more ram is good, but we are not in that position that we need 10GB or 12GB of ram, now 8GB of ram is more than sufficient for an android phone. But if you have not 6GB ram mobile or you can't effort a 6GB ram varient then don't worry, 4GB ram varient is also preferable.