The transfer of ownership of an immovable property from the previous owner to the new owner is considered valid only when the purchaser of the property pays the adequate stamp duty and the registration charges. A person is considered the legal owner of a property only after he gets the property registered in his name.
If a person fail to register the property, the previous owner will be considered the legal and rightful owner. The basic purpose of registration is to record the ownership of the property.
If the sale deed is not duly stamped and registered, then no right, title or interest in an immoveable property can be transferred. Further, in case of a dispute, a person will not have any rights on the property if it is not registered in his name.