Is my ipad version 9.3.5 compatible with 5g wifi?

Yes, but only at a maximum of 300mbps over 802.11n and only with WPA2 or WEP security. It won't connect if the Wi-Fi network is suing 802.11ac or later or has higher security than WPA2.

IOS 9?

WHAT IN THE WORLD IS THIS IPAD MODEL 2 OR 3 BUY A NEW ONE NOW 😡