I have modeled T's in the past.  The forces provided by the client MUST be in equilibrium.  Assuming this is the case, and orenting the T in with the cross arm at the top and the stem vertically, select a point at the top of the model where the axis of the stem intersects the top surface of the model.  Fix this point, it becomes the support point.
For axial forces on the ends of the T, divide the force by the number of nodes and place this force at each node.  For moments, calculate the force on each node as being porpotional to the distance of the node from the netural axis.  On one side of the netural axis these forces will be plus and on the other side they will be minus. Run the analysis, look at the support reactions.  Theoritically, they should be zero since the applied forces balance.  Practically, they will be very small numbers.

thanks eureka,

i am still not very clear. yes, i agree that axial force should balance in your case. but when the vertical forces are considered, the forces provided by client should be balance with the gravity of T and product?

The vertical forces should balance.  The shear force on the arms, the axial force on the stem, and the gravity forces, must sum to zero.

The horizontal forces should balance.  The axial force on the arms, and the shear force on the stem, must sum to zero.

The moments should balance.  The moments on the arms and stem must sum to zero.