Thankyou Richard for your reply.

Regarding the Lumped mass, I have keep it blank as this is an additional mass which I understand from your reply.

In My Dynamic Output > General Result > Active BCs,
Stiffness is showing zero for all the restraint which having the gap (more than zero) & Loads are showing zero for those restraint. What does it means ? & How I can get the loads for those restraint from dynamic output.

Also can we get the response spectrum for our system in graphical mode ?

Thanks
Dhiraj