For the ANSYS or NASTRAN solver you will need the software from ANSYS/NASTRAN and the according ANSYS/NASTRAN license to run the solver. Pro/MECHANICA FEM mode only acts as a pre-processor to create a model to run with the ANSYS or NASTRAN Solver. Note that Pro/MECHANICA wil require a specific version of these solvers, the latest version may not work (can be found on the PTC pages).