If you are doing Rigid Dynamics, a Bolt Pretension load is irrelevant as you are using rigid bodies.

In Static Structural, you might represent the bolt by a simple beam that is scoped to an imprinted face where the head would have touched on one end, and the cylindrical face where the threads would hold on the other end.  You can pretension this beam if you want.  You must also put frictional contact between the parts.

For an M5 bolt you must also say what the material is.  Only a Class 12.9 material can take a 12 Nm torque, which is very high at 100% of Proof Stress.  The threads have to be in a strong material like 1018 steel and have 15 mm of thread engagement. A more reasonable torque is 8.9 Nm which is at 70% of Proof Strength of a Class 12.9 M5 and requires only 10.6 mm of thread engagement in a 1018 steel. The clamp force is 2,166 lbf or 9,635 N for an 8.9 Nm torque.