Hi i am not able to add my card on wallet says there is an error

What is the exact error message your phone says?

See this link for help with adding a payment method to your account. Often the reason a payment method is declined is the card is issued in a country other than the country of the iTunes Store you are tied to. Could that be your issue?

See this for help --> If your payment method is declined in the App Store or iTunes Store - Apple Support

Here is another link about payment methods which are approved --> Payment methods that you can use with your Apple ID - Apple Support