Technically both the mechanisms are identical and similar and in both the modes the login and password of your net banking will be required. In case of payment gateway the extra step of creating and adding beneficiary i.e. 'Resonance Eduventures Limited' is not required.
In addition, the payment gateway mechanism makes a direct route of transfer of amount from your bank account to the bank account of Resonance, which makes it relatively simpler and faster.
We may keep a quick track of the receipt or failure of the amount for a quick confirmation to you in payment gateway.
Therefore, we advise you to prefer the payment gateway route as compared to NEFT route.