You Do Need power plug adapter while traveling from India to Gabon.

Here is Why You Need An Adapter

The outlet and plug type used in Gabon is C and in India are C, D and M. This is how they look like.

India

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

Type C

Type D

Type M

Gabon

In Gabon, outlets of type C are in use.

Type C