According to people who have reached expertise in the field of Vastu Shastra. The brass tortoise should be placed in the North or North West direction of the house. If it is placed in the correct direction, it will attract good vibes and good luck in the lives of family members, especially the children. It will sharpen the concentration level of the children as well.
Note: If you want to place a Tortoise which is made up of metal material i.e. brass, gold, or silver. It is recommended you place it in the North and North West direction of the house.