now you can easily root your karbonn A16 mobile...
Simple steps are here
>Download and install SRS One Click Root on your PC.
>On your phone, go to Settings > Developer Options and tick USB Debugging to enable it.
>Connect your phone to the PC using USB cable.
>Slide the notification bar down and make sure that your phone is connected as USB Storage. If it isn’t already, you can change it to USB Storage by tapping the Touch for other USB options notification.
>Open SRS One Click Root app on PC.
>Select the option that says Root Device (All method).
>After a while, your phone will ask if you want to install the application SRS Root is sending you over ADB.
>Tick the checkbox and select Install.
>When a popup appears on your phone asking you to choose the exploit, select Install SuperSU and click on Bormir.
>A Success message will be displayed on your phone as well as PC.
>Reboot your phone and check if you are rooted.
you can download SRS one click root from here
Mod Edit: Links removed because they were pay per clicks