Hello @Aditya Chavan Welcome to Microsoft Q&A community forum. Happy to assist you!
I see that you are trying to activate your Azure for Student subscription using your GitHub account and being greeted with message "University ID confirmation failure".
You need to provide a phone number and your academic organization’s email address (for example, your_name@your_school.edu) to sign up for an Azure for Students subscription.
Are you sure you're using your education's organization's email address? Please refer to the Microsoft for Students FAQ over here: https://azure.microsoft.com/en-us/free/free-account-students-faq/
If you're eligible, then I suggest you create a support request over here: https://azure.microsoft.com/en-us/support/create-ticket/. The ticket enables you to work closely with the support engineers and get a quick resolution to your issue.
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