How to get gantt datasource.. after reordering tasks

How to get gantt datasource,after reordering tasks. am using gantt.getTaskByTime() method to get it bt unfortunatly its gives datasource as initial data source

Hello Ramani,
You can get all tasks by using the gantt.serialize() command:
https://docs.dhtmlx.com/gantt/api__gantt_serialize.html

That command returns all tasks in order, but all their temporary properties (that start from $ and _) are removed.
If you need to save those temporary properties, you need to use the eachTask method and save all tasks into an array:

var all_tasks = [];
gantt.eachTask(function(task){
  all_tasks.push(gantt.copy(task))
});

https://docs.dhtmlx.com/gantt/api__gantt_eachtask.html