in GRE test. We do not know where to go and who to contact.?

go to [Only registered and activated users can see links. ]

u can find the list of test centers.Look for the one nearest to u.apply online in the above mentioned site and payment can be made using an international credit/debit card

Here is the answer ...

Please when I say YOU, it means your son.

YOu need Credit Card to register GRE online.

First Register GRE Test on GRE.org, you might not be able to find the link to register GRE online so here is the direct link
[Only registered and activated users can see links. ]

There is the option to choose the city, there are only few cities of Pakistan for which you can choose so you should choose the city near to your city if you city is not there for example if you are in some city of Sindh other than Karachi then you should choose Karachi for your city and similarly I guess there is only lahore for Punjab.

Once you will finish the registration you will receive the email from them with all details. please me sure to get the backup of this email because all the details are there in email.

YOu need Passport and NIC as a proof of your identity when you will appear in your GRE(Both Passport and NIC are required)

More info at [Only registered and activated users can see links. ] even though its very confusing site.

Regards,
KK