Restrict products from being shipped to specific regions.
Restrict shipping a product to a specific region(s). If the user has an IP address in the region(s), they can be shown a message on the product view and cart item that the product is flagged. If they try to checkout with a shipping address in the restricted region, the product will be removed from their cart.
Upload the extension files to your server. In the admin under System -> Configuration -> Catalog -> Catalog -> Restricted Product, configure the extension:
On the front end, the flagged product will show on the product view and checkout cart:
On checkout, if the shipping region/state is the restricted region(s), restricted products will be removed from the user's cart: