You Do Need power plug adapter while traveling from Brazil to Mauritius.

Here is Why You Need An Adapter

The outlet and plug type used in Mauritius are C and G and in Brazil are C and N. This is how they look like.

Brazil

In Brazil, outlets of type C and N are in use.

Type C

Type N

Mauritius

In Mauritius, outlets of type C and G are in use.

Type C

Type G