how to add a lighting in the roof??
Do you mean how to add the ceiling windows? If so look for the "Redhouse" items on the search and you will find the ceiling window.
Or if you mean how to add pendant lights - these are on the sofa tab - search for lights. These do not always show up directly in the preview. However if you mean can you make the lights be alight once you have them the answer is no - we cannot currently change interior lighting effects