How to simulate mosfet connected in Negative Side in anti series configuration Like     

M1               M2

D    1   S      S    2   D

I am getting OP with out giving any input to M2.

Let's get this clear: you're making a bipolar switch and you have series connected N-ch MOSFETs, with sources connected together (and presumably also gates connected together), with input at one drain and output at the other?

They will conduct a negative or positive input when both gates have V>Vto. If you leave one gate unconnected, it will conduct with one or the other polarity when one of the gates is not driven. This is because the driven MOSFET will conduct both ways, but the undriven MOSFET will conduct only one way, but through the body diode, so there will be a significant voltage drop. If you swap driven and undriven MOSFETs over, the pair will conduct only in the other direction.

Is that your situation?

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Regards,
Tony