If the subscriber is on auto-renewal mode (For example, using Google In App, iTunes Connect) then the subscriber does not need to worry about renewal.
The subscription will be renewed automatically using already mapped card credentials.
But if the subscriber is not on auto-renewal mode, in that case subscription can be renewed using payment methods/instruments which are available in the location from which the user got registered.
In case if the user is not able to make payments using payment instruments from registered location, then the user needs to register again and choose from the payment methods/instruments available in new location.