That's good news, you can run a 64b OS.
https://www.microsoft.com/en-us/software-download/windows10 That's not to say you can definitely run gta5, but you should have a 64b OS anyways really.
Yeah in my experience, on a desktop yet, 8gb of ram was just enough to play gta without stutters.
Anyways i'm assuming that @op is trying to play gta5 on their laptop that has a default 32b OS and 4gb ram. You most likely won't be able to play gta5 on that laptop, unless you have a dedicated...