--------------------------
--set up sample data
declare @products table (prodID int, Mens bit, Ladies bit, child bit)
declare @gender table (gender varchar(12))

insert @gender
select 'Mens' union all
select 'Ladies' union all
select 'Child'

insert @products
select 1, 1, null, null union all
select 2, 1, null, 1 union all
select 3, 1, 1, 1
--------------------------

select g.gender + ' (' + convert(varchar, 
       count(case 
              when g.gender = 'Mens' then p.Mens
              when g.gender = 'Ladies' then p.Ladies
              when g.gender = 'Child' then p.Child
              end
              )) + ')'
from   @products p
cross join @gender g
group by g.gender
order by 1 desc

OUTPUT:
Mens (3)
Ladies (1)
Child (2)