How to book slot for GRE? In the following post I will try to give a step by step guide Go to the official website of ETS. Choose a time slot 6. 1) Candidates can book their slot for the GRE ® test on the internet itself. The website address is www. bookaufrakostenlosspielen.review or www. bookaufrakostenlosspielen.review The website will. GRE is a computer-based test and is offered throughout the year by ETS, the (Don't worry; you DO NOT need to book the dates in order to check the availability.) Along with the date, also consider what time slot would be convenient for you.