How can I deduce the information if the keyboard is visible while device orientation is changed? Does this information is sent inside - (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)iFromInterfaceOrientation method?
Nope, you will have to subscribe to some notification and keep the info somewhere.
Have a look at
UIKeyboardWillShowNotification
UIKeyboardDidShowNotification
UIKeyboardWillHideNotification
UIKeyboardDidHideNotification