What is the legitimate right of my mother in a house that she participated in building with her money and effort (the first three floors), and then my uncles completed the construction of the remaining floors (the fourth, fifth, and sixth), and is she entitled to receive rent for her share?

The land and the house are a partnership between your mother and your grandfather, proportionate to the amount each of them paid. If one dwelled in it without the other, then the other has the right to demand their share of the rent. What your uncles built in terms of additional floors, with the permission of your mother and grandfather, is considered a gift from them for the airspace. Your uncles own what they built, and your mother cannot revoke this gift.