I knew by using console command, we cannot get achievement at that moment.

Then how about Mod?

Nah don't think so, not sure though

I use mods and I get achievements.

Mods don't interfere with achievements.

If you use a console command, saving, quitting and restarting New Vegas will re-enable achievement tracking.

The second mod I installed was the achievement remover.
(The first one was to greatly increase the distance open to the TPP camera ~NV annoyingly locked it to just three feet or so behind the PC. :bonk:)