You Do Need power plug adapter while traveling from South Africa to East Timor (Timor-Leste).

Here is Why You Need An Adapter

The outlet and plug type used in East Timor (Timor-Leste) are C, E, F and I and in South Africa are C, M and N. This is how they look like.

South Africa

In South Africa, outlets of type C, M and N are in use.

Type C

Type M

Type N

East Timor (Timor-Leste)

In East Timor (Timor-Leste), outlets of type C, E, F and I are in use.

Type C

Type E

Type F

Type I