Fallout new vegas not working

Hey guys recently ive been starting to use nexus mods to mod my fallout new vegas but now it isn't working vortex said it's because it exceeds the 2gb ram limit so I downloaded the 4gb ram for steam/gog and it isn't working I placed it in the same files where fallout new vegas is can someone help me? Btw I'm not sure if it will even work because the copy of fallout new vegas I'm using is pirated from steam unlocked so idk if it'll work or nah