Wifi stopped working just after i upgrade ios 6.1.2 to 6.1.3

Hi Gunjan,

Thanks for visiting Apple Support Communities!

It sounds like you've already tried a few troubleshooting steps, but these links may offer some additional tips:

iOS: Troubleshooting Wi-Fi networks and connections

http://support.apple.com/kb/ts1398

• If you are using a public or commercial network that requires a login or subscription, see this article for more information.
• Verify that you are selecting the correct network if you are in a location with multiple Wi-Fi networks.
• Verify that the Wi-Fi network settings are correct. You can view and configure Wi-Fi settings using the following steps:
  • Tap Settings > Wi-Fi.
  • Locate the Wi-Fi network you are currently using and tap .
• If you've verified that your settings are correct and the issue persists, try the following:
  • Tap "Forget this Network" to reset settings for this Wi-Fi network, including the password. Then try connecting to the network again.
    Note: This can be useful if you identify a network issue and want to prevent the device from automatically using this network in the future.
  • Reset network settings by tapping Settings > General > Reset > Reset Network Settings. Note: This will reset all network settings, including passwords, VPN, and APN settings.

Note: If the Wi-Fi network uses MAC address filtering, you will need to add the MAC address to the access list for the Wi-Fi router. The MAC address for your device is listed as the Wi-Fi address in Settings > General > About.

If this issue persists with multiple wireless networks, see our general iPhone Troubleshooting Assistant for more steps you can try:

http://www.apple.com/support/iphone/assistant/phone/

Best,

Jeremy