By Mistake i deleted system folder from root file and my mobile was rooted from then my mobile not working what can i do? By Mistake i deleted system folder from root file and my mobile was rooted from then my mobile not working what can i do ? usb debbug is off flah file not found "reach cogent colours" plzzz help me ........
The only thing you can do in that situation is to flash a ROM. If you can flash the same ROM you just were using, you could even do a "dirty flash" (i.e. without wipe), so your settings and data stay intact.

For details, please see our rom-flashing tag-wiki and follow its links. What tools you will need depends on your device (which you didn't name). If you don't know where to find a ROM for your device, please refer to Where can I find stock or custom ROMs for my Android device?