Yes, if you mean the same program globally, you can have a mix of Ladder, Structured Text and Function Block Diagram all in the same program. If you right click on "Programs" you can "Add" a new program using any of the three programming languages.
The attached example shows all ladder with the bottom program in ST...
If you mean within the same program locally, then no. As explained, when you add a new program it will be predefined for one of the programming languages.