I have lenova A6000 android mobile. when i try to download apps it shows "insufficient storage space". but free space is there(800 kb) cant add apps even 10 mb.
800kb is absolutely not big enough. Lenovo A6000 has 8G memory and 1G RAM, which is very limited for apps nowadays. Do you have a SD card? Some apps can be moved to SD card so that you'll get more available space.