Hi @Ashikh_P_M,
a Task is usually completed once. If you want to execute it multiple times with different assignees you can use a multi-instance task marker. (See https://docs.camunda.org/manual/latest/reference/bpmn20/tasks/task-markers/#multiple-instance)
You can pass a collection of assignee names to the task. This has been discussed in this topic.
Cheers,
Miklas