string tableName = cboSelectTable.Text.ToString();
var comboBoxColumn = from a in Context.RULES where
                     a.ISCOMBOBOXCOLUMN == "Y" select a.COLUMN;

foreach (var colName in comboBoxColumn)
  {
    var getTableName = entityModel.GetType()
                                  .GetProperty(tableName)
                                  .GetValue(entityModel, null);
    var getData = ((IQueryable<object>)getTableName)
                                      .Where(colName + "!=null")
                                      .Select(colName)
                                      .Distinct()
                                      .OrderBy('"'+ colName +'"');
    dgvCboColumn(getData, colName);
  }

var getData = ((IQueryable<object>)getTableName)
                  .Where(colName + "!=null")
                  .OrderBy(colName)
                  .Select(colName)
                  .Distinct();

var getData = ((IQueryable<object>)getTableName)
                  .Where(colName + "!=null")
                  .Select(colName)
                  .Distinct()
                  .OrderBy("it");

SomeList.OrderBy(l => l.SomeAttribute);