Log in to your Microsoft account (https://account.microsoft.com/account/manage-my-account) and review your purchase history or billing information. This should show details about the transaction, including what it was for.
If the information in your account isn't clear, contact Microsoft support directly. They can investigate the transaction and explain the reason for the 83 rupees deduction. You can find contact information on the Microsoft support website (https://support.microsoft.com/en-us/contactus/).