select x.category, Closed_count, Created_Count
  from (select a.category, count(*) closed_count
          from table1 A, table2 B
         where B.CATEGORY = A.CATEGORY
           and B.DES= 'Books'
           and TRUNC(A.DATETIME_STAMP) >= to_date('01-01-2011','DD-MM-YYYY')
           and a.status = 'C'
         group by a.category
               ) x
      ,(select a.category, count(*) created_count
          from table1 A, table2 B
         where B.CATEGORY = A.CATEGORY
           and B.DES= 'Books'
           and TRUNC(A.DATETIME_STAMP) >= to_date('01-01-2011','DD-MM-YYYY')
         group by a.category
               ) y
 where x.category = y.category
 order by 1
/

CATEGORY   CLOSED_COUNT CREATED_COUNT
---------- ------------ -------------
Books                20            30

1 row selected.

SELECT
  B.Category,
sum(decode(a.status,'C',1,0)) closed,
sum(decode(a.status,'C',0,1)) open,
sum(1) created_count
 FROM
                Table1 A ,
                Table2 B
  WHERE  
                B.CATEGORY = A.CATEGORY
            AND B.DES= 'Books'
     AND TRUNC(A.DATETIME_STAMP)    >= to_date('01-01-2011','DD-MM-YYYY')           
group by B.Category;