Within 15 days your number will be changed from old number to new number. Within 15 days is the approximate time for changing your Aadhar card details but if it's not changed within 15 days then within 20 to 25 days the details will be changed for sure.
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If the server is too busy with changes then it takes long time to change, if the server don't have much users for correction Within 2 weeks the work will be done