well, it depends on the standards you expect from those nusery schools. If you are looking for a perfect one then you must go around and gather info about them. You are of course always allowed to go in and interview the teaching staff and view the basic setup/safety measures/hygiene etc and this will allow you to decide whether they meet your expectations or not. However,if you want your child to be in a British Nursery then he should be 3 years old by the 31st of August xxxx.
Hope you will find a good place
Best,