there is any way to put NPC s in the map?

I would like to know too. There just aren't enough mobs in NV and until Mad Martigen puts out a version of MMM for NV I'd like to learn how to make changes in numbers of Fiends, Vipers and Jackals oh and Deathclaws and Ferals too. You might try "More Fiends" on Nexus since it adds some fiends (imagine that) - if I could figure out how to change the numbers in the GECK I would start by making modest changes and maybe work up from there. The author of "More Fiends" has posted images on the mod page - numbers before and after the mod. That might give you an idea I found the correct entry in the GECK (I think), but it won't let me change them.

Hopefully someone will point us in the right direction.