Whilst rescheduling a tasks, if the user needs to reschedule multiple tasks this can be achieved via bulk rescheduling of tasks feature from linked task screen.
Using this feature will allow the user to reschedule both linked tasks and normal tasks from one screen.
Go to linked tasks screen and tick the check boxes next to the tasks to reschedule them. You can also use +/- to increase or decrease the dates for rescheduling. Only the tasks which have the check box as marked will be rescheduled.