1.  @Html.DropDownList("LevelMaster", (IEnumerable<SelectListItem>)ViewData["LevelMaster"], "Select Master")

2.  <select id="BranchID" name="Branch"></select>

There is no ViewData item of type 'IEnumerable<SelectListItem>' that has the key 'LevelMaster'.

 <span>
  @Html.DropDownList("LevelMaster", (IEnumerable<SelectListItem>)ViewData["LevelMaster"], "Select Master")
 </span>