You can verify your US AdSense account through account through US based mailing companies that receives letters for people outside US to scan it and send it to their mails. Below are the two lists I know!
Travelingmailbox.com is one of the good ones to use in receiving your pin and it has worked for my friend. As soon as your PIN arrive the given address, it will be scanned to your inbox.
Before they scan your pin and send it to you, they will request for ID card. They won’t tell you what ID card they need but after your parcel arrives, you will be asked to fill a form (I have forgotten the name of the form). the form contains your details and you will be asked to upload two ID cards, before they proceed.
You can read more about them on their site Travelingmailbox.com.
usglobalmail.com is a new way i found out but I have not tried them out. You can google more about them and also contact them on their site to know more things about their services.
You can also receive your US AdSdense pin through someone living in US!