If you are a Vodafone India user, here is how you can reset your forgotten Vodafone India password.
Visit below link :
https://myvodafone.vodafone.in/portal/page/portal/myvodafoneselfcare/forgotPassword
You will be prompted to enter your login Id which should be your mobile number. Upon entering it will show you the secret question which you might have entered during login creation time, just enter the answer of the question and the letters displayed in the captcha.