The GRE revised General Test is administered around the world. The list of available examination centers (see links below) is continually updated, and contains the locations that currently offer the exam. Computer-based testing for the GRE is available most often at Prometric™ Testing Centers, and at many colleges and universities. Regardless of where you take the exam, the exam environments have been designed to be very similar at all locations. You will always be asked to show you identification and registration slip, and you will be supervised while taking the exam.
It is crucial that you look for an exam center that is close to your home. And, when you do find that center, be sure to sign up as soon as possible for your desired date and time. This is very important, because exam appointments tend to fill up quickly, especially towards the end of the year when applications to graduate schools are due. If your exam center is far away, and you have to travel several hours to get there, then there is a greater chance that you will be tired when you take the exam, or that you'll be delayed because of the trip.
For the computer-based GRE revised General Test, ETS provides a list of computer-based exam centers that you can access online. For the paper-based general exam, find your exam center in either of China, Hong Kong, Korea or Taiwan, or locate it on the Information and Registration Bulletin and Forms page on the ETS website. There you will find PDFs of lists of examination centers and registration centers for both the paper based and computer based exams.