There are lots of places where you can find practice ISEE questions, but you should only work with official ISEE questions from the company that makes the ISEE, because those questions are the only ones that are guaranteed to behave the same way that real ISEE questions will behave on test day.
The ERB, which is the company that makes the official ISEE, maintains a page at this link that will allow you to download a free pdf with real practice questions in it. All you have to do is fill in your state of residence, your grade, and whether you’ll take the test this year, and then press “submit”–after that, the site will give you the appropriate pdf for your level of the ISEE.
I can’t stress enough how important it is *not* to use fake ISEE questions. A lot of web sites and companies make up their own ISEE questions, and these made-up questions often have nothing to do with how the test really works. If you practice for the ISEE with fake questions, there’s a very good chance that you’ll end up developing the wrong instincts.
This applies even to books of fake questions made by “reputable” companies like Kaplan, Princeton Review, Barron’s, and so on. If you want to make sure you’re really prepared for the real test, you have to work with real questions.