If I am getting sms of verification code for keychain and after put the same code it still says verification failed. You hv entered too many times wrong no. Which I did not. What is the problem with keychain then

You are not alone. But no worries, just reset your keychain and setup again.

iOS:

1. In iOS 8, tap Settings > iCloud > Keychain > Advanced. In iOS 7, tap Settings > iCloud > Keychain.
2. Tap Approve with Security Code.
3. When asked to enter your iCloud Security Code, tap Forgot Code.
4. Tap Reset iCloud Keychain to replace your iCloud Keychain in the cloud with the iCloud Keychain items on your device.
5. Tap Reset to confirm. You'll be asked to create a new iCloud Security Code.