minimum system requirement of total war rome II is
CPU: 2 GHz Intel Dual Core processor / 2.6 GHz Intel Single Core processor
RAM: 1GB RAM (XP), 2GB RAM (Vista / Windows 7 or 8) GB RAM
OS: Windows XP / Vista / Windows 7 / Windows 8
Video Card: 512 MB Direct 9.0c compatible card (shader model 3)
Sound Card: Yes
Free Disk Space: 30 GB
So yes, you will be able to play that game, but merely at low setting..
i suggest you to upgrade your graphic card..well, it's depend on your budget..