come on arti .....have you seen the Gallery ??? ...dont be upset !!! how have you done this images, corona is almost a "DONT MISS" renderer.
Are you new in the CG imagery.????
there are serious mistakes here in your images, first is the camera view i think is not well, in second try to put, in the environment an HDRi of a night sky ( on render setings)( that way you will use the light from the Map, global ilumination ( have ear about it )
Im really not an expert in this area, but there is still a long way to go for you,and another advise i can give you, pay attention to the really good images in the gallery and try to copie them ( make something alike) and have a critical view, in what you see, AND more important IN WHAT YOU ARE DOING ....
OK ... im a joker but i dont want tu upset nobody,
Just look a your images ...and look at some good images in the gallery ( So!!! what can you tell me (critical view ok!!) ( it needs more passes, right.... the camera view its not right .... and....????)