Greeting,
I use the default Revit family pile. It is structure foundation type but it doesn't have the option to place the rebar. The family is attached. Any help would be appreciated.
Place rebar in structure foundation
Accepted solution
You cannot place the rebar because the pile defined as steel pile, to change it do the following steps:
Open it in family editor > go to family category and parameter 
Save the family and reload it to the project.
Hello,
I have a follow up question. I created a revit family and set model behavior to concrete. However, it doesn't work as expected in project. The file is attached. Do you mind help me take a look?
Thank you very much for your help!
I believe that you want to extend the steel pile inside the concrete one.
If so, you can't do it in the current status, because by default Revit will not allow you to extend the steel pile (which has structural column category) inside the concrete pile (which has structural foundation category).
To solve this issue you have many solutions:
1- Use the steel pile family (structural foundation category) as per the following photo:
you can extend this one inside the concrete pile
2-Insert steel column family (which you are using in your photo), inside the family of concrete pile, extend the steel pile and modify the family accordingly, then reload the family into the project.
3-Use structural column category to create the concrete pile, then insert the steel column inside the concrete one.
