Ok. I have downnloaded some mods from Fallout NV Nexus. Installed them with NMM and game didnt crash. but, I have trouble finding the location of two of these mod made houses. Here are the links.
http://newvegas.nexusmods.com/mods/36121#content
http://newvegas.nexusmods.com/mods/46004
and this
http://newvegas.nexusmods.com/mods/46278
Can anyone help me?

You can check them all in fnvedit and see what worldspace they are in.

where is tha thing that you mentioned?

http://newvegas.nexusmods.com/mods/34703

I downloaded it but dont know how it works.

It goes to your main falloutnv directory. You load up the mods whos houses your looking for as it loads up. Afterwards you expand the plus next to each mod and expand (sometimes several expandings) their worldspace headings and it will show you what exterior cell they are in.

If you have to go to all this trouble to find out where those houses are, the readmes for those mods must be sorely lacking in any useful info.