your final sql will be as follows :

this code below deletes only first found row of row sets having the same value for the column nvarchar1 and the value of 1 for the column int1

declare @varchar1 nvarchar(50)
declare mycursor cursor for
select varchar1,
from mytable
group by varchar1
having count(*) > 1

open mycursor

FETCH NEXT FROM mycursor INTO @varchar1
WHILE @@FETCH_STATUS = 0
begin

delete top (1) from mytable where (@varchar1=varchar1 and int1=1)
FETCH NEXT FROM mycursor INTO @varchar1
end

close mycursor
deallocate mycursor