Getting the ball to come back

sir,

i have tried a lot of time to make the ball come backward after the service is done.

how should the movement of the racket go.to make the ball spin backward more 

Hi Vivek,

To get more backspin, try getting the angle of your bat even flatter.  You can even face it a little to the back wall. This may feel and sounds strange, but give it a try.

The best way to start to get the backspin, is to step away from the table and see if you can get the ball to spin back towards you on the floor.  Have a good swing at the ball to generate more backspin.