Here are additional details I got from our technical team adding to Swaathi's answer… Hope this is clear. The client limit for Aruba Instant On is per SSID per AP. It is not related to the number of APs in the site. This too is independent of the number of clients connecting the same SSID on other APs.

The limit is 64 connecting to a single AP SSID at 2.4GHz and another 64 connecting to the same AP SSID at 5GHz. You can add a second SSID and have the same max number of clients on that AP's second SSID as each SSID has its own limit. But at that point you’ll hit another limit which is upper limit of total clients per AP. That's it. No more.

Total AP for virtual controller: 128 AP

Total devices for Frecuency: In 2.4 Ghz … Max: 64 clients can be connected, and in 5 Ghz max; 64 clients can be connected.

Totally 128 devices can be connected per Network for AP.