UNABLE TO PAY THROUGH MY CREDIT CARD?

Please visit your credit card issuing bank website and get verified your visa card there. Like wise get verified for MasterCard secure code if you are using master card. This will make your card 3D-Secure or 3DS. It is compulsory condition to get verified your visa card from your card issuing bank website to do international payment. Without this you will not be able to pay your purchase from India. The reserve bank of India will not allow this.


What is 3DS and how it works?
Three Domain Secure (3D-Secure or 3DS) is a security protocol supplementing online transactions made using cards by authenticating cardholders with one time password (OTP). 
While processing transactions secured by 3DS, cardholders will be redirected onto their respective Issuing Banks’ page to input OTP sent via SMS to their registered mobile number , USSD, or email. This service may otherwise be recognized as Verified by Visa (for Visa cards), MasterCard SecureCode (for MasterCard cards), J/Secure (for JCB cards), or Safekey (for American Express cards).

I hope it will solve the problem for all your future international payments.

Note: 
Read this link to get more clarity  https://www.visa.co.in/pay-with-visa/security/secure-online-shopping.html