secondary sidebar changes its location

Hi to all, I am new in wordpress. My question might have a simple solution, therefore I am sorry if I am taking your time..
My problem:
I have used many free templates with three columns (left/right sidebars) but when I press the category from menu, whole structure of page change…
the secondary sidebar changes its location and it goes to below of page ..
I attached two photos before and after of clicking on category
Before clicking on category or archive file —->
After clicking on category or archive file —->