If you're going for realism then there is some work to do. I'm sure you know that the level of disarray and destruction needed to realistically portray a believable apocalyptic scene needs a certain amount of detail and that results in some serious memory and scene management. This is a big job, get ready for some crits! 
Some things I noticed with the scene:
-Modeling. The buildings could use some more detail as currently they seem kind of flat. Details like deteriorated versions of objects often seen in street scenes like traffic and building signs for example. Has it been long enough that there is vegetation overgrowth, trampled trash and grime? There is some rubble but not much else.
-Texturing. Seems like the textures could be a bit higher res and detail. The light poles and a couple of the vehicles look rather clean. The rust on the other two vehicles don't seem organic, if you Google rusted vehicles, streaking patterns are common so is corner or crevice rot. The cracking texture on the left building seemed kind of sprawled over it and seem unnatural.
-Lighting. Not sure of the weather conditions. The soft shadows say "overcast" but the clear blue sky betrays that. So I'm not sure of the direction you'd like to take that.
-Shot framing. It's tempting to cram everything into a shot because you spent time making them but that doesn't always make an interesting image. Check out photography and cinematography tips.
Keep at it and keep posting!
Oh... Thank you so much for your response Gen... And for your continuous support... I really appreciate and will make those corrections and post the corrected version.. . About the details needed for the post-apocalyptic scene needing chunk of memory space.. .true.. . I feel I'm already maxing my system's memory out... But, I guess those are the prices to pay...