One member of the family becomes the Family Organizer. This is considered the main account, who organizes the "family plan" called Family Sharing. S/He adds other members to the Family Sharing plan.
I think: each member's Apple ID has to belong to the same region so that the Organizer can add members to the Family Sharing plan. It does not matter what your actual geographical location is. (You could be residing in India but could be using an Apple ID associated with the USA region, for example.)
So if all of you have an Apple ID associated with the same region, it could be possible.
Family Sharing - Apple Support
Use your own Apple ID for Family Sharing - Apple Support
What types of content can I share with my family using purchase sharing? - Apple Support