@Nikhil M If you are running a transient simulation and the delay is in the calculation of the initial DC operating point tou can try setting all voltage sources (including supply voltages) to 0V at time=0, and then let them evolve as required for your simulation. In this case the initial DC operating point is trivially calculated (all voltages = 0). Another possibility is to force initial condition on some nodes (using the .nodeset instruction) if you know the initial state.
You may also try to use the UIC option in the .tran instruction; from ngspic man:
uic (use initial conditions) is an optional keyword that indicates that the user does not
want ngspice to solve for the quiescent operating point before beginning the transient
analysis. If this keyword is specified, ngspice uses the values specified using IC=... on the
various elements as the initial transient condition and proceeds with the analysis. If the
.ic control line has been specified (see 15.2.2), then the node voltages on the .ic line are
used to compute the initial conditions for the devices. IC=... will take precedence over
the values given in the .ic control line. If neither IC=... nor the .ic control line is given
for a specific node, node voltage zero is assumed.