Dear Shiladitya,
Apologies for my delayed response.

In amset, ntype doping concentrations are specified by negative doping concentrations, and ptype carriers are specified by positive doping concentrations. See the documentation for more details.

In general, people discuss two dielectric constants:
 The highfrequency dielectric constant (\epsilon_\infty), sometimes called the “optical dielectric constant”, is the value deduced from the refraction of electromagnetic waves with frequencies high compared to lattice vibrations (phonons).
 The staticdielectric constant (\epsilon_\mathrm{S}) is the total dielectric screening from the highfrequency response and the vibrational response (lattice). I.e, static = highfrequency + ionic dielectric constants.
Unfortunately, the terminology used by VASP for the dielectric constants is not very precise. If you do a DFPT+LEPSILON calculation, as described in the calculation section of the documentation, the OUTCAR will contain a number of dielectric constants, each with very similar names.
For example, these are taken from the OUTCAR for a DFPT calculation on SnS.
MACROSCOPIC STATIC DIELECTRIC TENSOR (including local field effects in DFT)

17.540787 0.000000 0.000000
0.000000 21.425820 0.000000
0.000000 0.000000 17.487301

...
MACROSCOPIC STATIC DIELECTRIC TENSOR IONIC CONTRIBUTION

19.848112 0.000007 0.000001
0.000007 41.125796 0.000008
0.000001 0.000008 21.693346

Here, the first dielectric constant is actually the highfrequency dielectric constant NOT the static dielectric. The second tensor is the ionic contribution to the static dielectric. To get the final static dielectric constant you have to take the highfrequency dielectric + ionic contribution.
Therefore, the inputs to amset would be:
static_dielectric:
 [37.39, 0, 0]
 [0, 62.56, 0]
 [0, 0, 39.18]
high_frequency_dielectric:
 [17.54, 0, 0]
 [0, 21.43, 0]
 [0, 0, 17.49]
I hope that helps.
Best,
Alex