If I Go To Other Countries Like Nepal, Is It Possible To Register For The Current Gre?

According to the Commission for Educational Exchange between United States and Nepal, it appears to me you probably could take the GRE in Nepal. Apparently, the test is given three times a year: April, November, December at the Saint Xavier School, Jawalakei, Kathmandu, at a  cost of $150 American dollars.

I found a website address www.gre.com however, I was unable to get the link to work. Then,  I found the link with a Bulletin packed with information about GRE. In a listing of the Regions, Nepal is in Region 6 the address is Prometric, PO Box 12964, 50794 Kuala Lumpur, Malaysia. The email: searrc@thomson.com You may want to send an email or a letter of inquiry to Prometric, which is the name of the group, who administer the test; ask your question of them.

The other places located in Region 6 are Australia, Bangladash, Hong Kong, Indonesia, Malaysia, Pakistan, Phillipines, Singapore, Talwan, Thailand. The country Code for the United States is 592, but the United States is not listed in a Region. In the Bulletin you may need to find the State Code for the State, in which are living.  

Go to this site for information and guidance: www.ets.
org/Media/Tests/GRE/pdf/0607_gre_bulletin.pdf  
The bulletin is long, I recommend giving special attention to Table of Contents, so you can find what you need easily.
Good Luck!