Select Statement

Experts,

Here is the SQL I am running and no problems with the SQL.

select       T1.Column1,T2.Column3,count(T1.Column6) as TestColumn1
from       Table T1
inner join Tablle2 T2
on T1.Column1 = T2.Column1
where       T1.Column1 > 'myvalue'
group by  T1.Column1,T2.Column3

union
select       T1.Column1,T3.Column3,count(T1.Column6) as TestColumn1
from       Table T1
inner join TempTablle T3
on T1.Column1 = T3.Column1
where       T3.Column3 > 'myvalue'
group by  T1.Column1,T3.Column3


I need to add one more column to my select and the output or the result of the newcolumn is like following.

C1 C2  C3   NewColumn
A   100     1          1
B    200     0          2
C   500     1           3
D   720     1           4


if my select gives 2 rows, newcolumns values should be 1 and 2
if my select gives 10 rows, newcolumns values should be 1 to 10

Thanks in advance and let me know if the question is not clear.