Answered on November 21,2020
This has happened due to the mode of user account creation. In this case, the user has created the user ID for a new ration card. So here he can see only two options,ie., New ration card and Add transferred card. He should have created the user account for making changes in an existing card. In that account, he can see many options and from that options, he should select "General Details" to change his mobile number.
Follow the steps mentioned below.