Hi @ashis sahoo ,
one reason for the error message "You're not eligible for an Azure free account"
could be the email address was used in the past for an Azure free account.
Same if the credit card was used for an Azure free account before.
Third reason could be invalid address information, phone number or email address.
More details you will find here: You see the message 'You are not eligible for an Azure subscription'
(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)
Regards
Andreas Baumgarten