If you are connected to Wi-Fi but cannot access internet on your apple device then this instruction page will surely help you. User need to have wireless router and network connection (broadband or dial up) in order to access internet on iOS device. All you need to do is just follow the below mentioned steps to resolve internet issue on iOS device.
Step 1: Firstly, make sure the data/internet LED is on router. If it is working on then disconnect the Wi-Fi connection and connect it back. Reboot the Router in case LED light is not working.
Step 2: Reboot your iOS device. You can also perform soft reset before connecting it to network. Disconnect the main input cable from router and connect it back. Make sure power adapter is connected to wall outlet.
Step 3: The above mentioned steps will definitely help you. If still data/internet LED is not blinking on the router then it is advisable to contact ISP (Internet Service Provider).