Placing a puja room in the North-east zone of the home is the most suitable zone according to Vastu Shastra. However, if this is not available, the West or even East zone can be used as an alternative. It is important to ensure that the puja room is kept neat and clean, and that all the religious items placed in it are of good quality. Additionally, it is important to avoid clutter, as this can have a negative effect on the energy in the room.