You Do Need power plug adapter while traveling from Nepal to Cocos (Keeling) Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Cocos (Keeling) Islands is I and in Nepal are C, D and M. This is how they look like.

Nepal

In Nepal, outlets of type C, D and M are in use.

Type C

Type D

Type M

Cocos (Keeling) Islands

In Cocos (Keeling) Islands, outlets of type I are in use.

Type I