Limitation to models qty

[TanvirAlam]

is their any limitation to add number of models. what is the limitations??

[Puybaret]

Limitations may come from the max memory allocated to Sweet Home 3D (read theFAQ if you want to increase it), and probably from your graphics card for the 3D view and the photo rendering at the two lowest quality levels.
Many models to handle mean also more data to process and more processing time, which could lead to slowdowns if your CPU isn't powerful.