@User, I am getting below errors(no such vector & dynamic gmin stepping failed) on simulating extracted spice(along with parasitic extraction) file from layout. On extracting same layout without parasitic extraction ,the extracted spice is simulating with no errors. I am not sure what is causing this issue.

Have you checked the nodes mentioned in the error message? Having a look at the netlist and comparing between the work and not working should give you some hints

@Deepak: Also: If magic has extracted any "floating" nodes, then ngspice will fail to converge with these in the netlist unless you either get rid of them or set a minimum leakage resistance per node (.option RSHUNT=<value>); this can be set to some ridiculously high resistance like 1E12 which will keep it from affecting circuit behavior, but it will prevent the issue with failure to converge.

@Tim Edwards , extracted spice does not have any floating nodes. I was getting nodes as $SUB , so included .magicrc file in the same directory so that it has taken VSUBS.

And that solves the issue?

No.. That doesn't solve the issue... But now I got it was different issue which is related to some net naming in cell which is creating issue when used in top level