Project block to a surface

I have been trying to look for a rhino or grasshopper script that enables to project blocks to a surface.
I am aware that there were some discussions similar to this, but I was not able to find one that works with blocks.
To be specific, I have made a tree block, and I want to project or drop it on to the terrain surface.
Please let me know if there is anyone who had solved it.
Thank you for your help!