Optimating shapes arranges in boundry polygon

hi, so I have this site, in given shape, and I made 10 different rectangles in order to find a good way to arrange them in the site.
i can’t to understand how to make sure that the rectangles won’t get out of the site, and get me several options with the galapagos, and keep them form collide with each other.
before you tell me to do it in phyton or C#, I have no knowledge about it.
I tried to use the plugin Packrat, but unfortunately, it works only with rectangle site, which its not the case with my site.
even tried open nest, but it didn’t help.

in the image you can see the blue curve - its the site.
the black rectangles are the base for the volumes in the image. I thought that if I will start in 2d shapes it will be easier for my to arrange the volumes in the site.
and thus small volumes were my manual attempt to arrange them in the site, which Excessively inefficient.