The iOS 6 let you allow to set up multiple Email signatures on your iPhone, iPod Touch and iPad, for different email accounts you have enabled in Mail app. So if you are interested to know about the process to do so then check out the guide written below.
Set up Multiple Email Signatures in iOS 6
Tap on “Settings” app on your iDevice and then tap “Mail, Contacts and Calendar settings”
Navigate to “Signature” > “Per Account”
Write Signature text in boxes for different accounts there and that’s it