Is it possible to pass parameters to js controller in lwc

You can read data directly from the target:

<div data-id={task.taskId} class="draggable" draggable="true" key={task.taskId} 
  ondragstart={handleDragStart}>{task.name}</div>

---

function handleDragStart(event) {
    var taskId = event.target.dataset.id;
    // ...
}