booting Android lenovo A6000+ I am using lenovo A6000+ phone. 

I have rooted it earlier with kingroot app, and recently there was system update, so I downloaded update and tried to install it but at the time of rebooting there were options for system recovery, first I choose to "install update from adb sideload" but that gave me an error. so I again restarted my phone and clean the cache, then again rebooted and chose adb sideload but there is nothing happening. 

So I again rebooted and chose factory reset. But even after doing factory reset to my phone, it is still giving me options for system recovery. 

How can I start my phone, can I install that update externally and start the phone and how?
the update fails because you have modified the system partition with your root. I don't know what you can do to revert these changes, but you can simply install cyanogenmod on your phone