Add a custom Panel to the gantt

How Can I add a Custom Panel, However i want to perform a drag event when a item from the panel drag to task

Hello Subhasis,
You can add the panel by specifying a custom HTML content in the layout config:
Here is an example of how it might work:

Then you need to add a function that will allow you to drag elements into Gantt and add tasks after that. Here is another snippet with that function:

If you combine those snippets, you might get something like this:
After you drag a picture into the grid, a new task will be added.