I am unable to discern anything useful from your photo, due to its poor quality and non descript content.
Try and look for any labels or numbers written on the motor, perhaps you can find a part number or spec. Google any numbers/words you find if you don't come up with anything post them here either as a quality picture or typed (ideally both ways) and we can see what we come up with.
If u cannot identify.........then do you know any such kind of motor which can
rotate 2-3 kilogram of weight effeciently?How can i get it?
This is not sufficient information to spec out a motor, you need to identify any static and dynamic loads on the motor, such as acceleration . You also need to identify the speed and voltage at which it will operate. Additionally there are different types of motors to chose from and some may have extra features such as an encoder or brake.