It depends on what type of users and what is the purpose. You first need to check what type of environment you have, is this educational, hospitality, public venue, office etc ? Once this is done below link will be able to help you with the correct AP as per your requirement/deployment area. In the below link go to "Wireless access point look up guide" where we have suggestion as per the project. Then you can also go to "filter" and chose concurrent user which is 256, 512, 1024, 1536. Once you have AP selected and still have doubt you can even compare the APs specs using "compare" to be 100% sure.