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

Here is Why You Need An Adapter

The outlet and plug type used in Croatia are C and F 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

Croatia

In Croatia, outlets of type C and F are in use.

Type C

Type F