Question

why we can hit a long six in a cricket match rather than if we toss a ball for our sleeves?

Answer 1

Think about the mechanics. If you throw a ball in the air to hit, you have to quickly move your body to lift your body to hit the ball. When someone bowls at you, you can already be in position when the ball arrives which will allow you to apply much more force. You also have more options in how you hit the ball. You can use the velocity of the ball to your advantage (hooking or cutting) or by walking to the ball to hit it harder.