Jerk Rack Adjustment
How much difference there is between your clean and jerk rack positions will generally dictate how dramatic the adjustment between the clean and jerk will need to be. Certain lifters are built such that they can move the hands and elbows into position for the jerk without moving the bar at all. This is unusual, however—most lifters will need to pop the bar up off of the shoulders momentarily to shift the hands into position.
This adjustment can be done after standing completely from the clean by using a little upward drive of the legs to unload the bar from the shoulders just enough to move the hands, but this is a waste of time and energy and should only be used as a last resort.
Instead, the lifter should use the upward momentum already generated by the recovery from the clean to drive the bar up off the shoulders to create space for the adjustment. That is, finish the clean recovery aggressively all the way to the full standing position so the bar jumps up off the shoulders a bit, adjust your hands, and settle in your new position to prepare for the jerk.
Read more about the clean rack position and jerk rack position in this article