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

Here is Why You Need An Adapter

The outlet and plug type used in French Guiana are C, D and E 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

French Guiana

In French Guiana, outlets of type C, D and E are in use.

Type C

Type D

Type E