Hello any guide , advice , tips to how should I do to make Custom objects Lods?

OFC apart from building a low poly version of the object , how do I do to then make it lodificable by the game ?

When you double click on the static in the Object window, put a tick in the box that says 'Has Distant LOD'. The long grey button now becomes functional. Click it and then browse to your LOD .nif for the different levels of LOD

but how to point the generation of lods do I need to make tga files or what?

When generating object LOD the CK looks for any TGA textures related to the lod meshes it's generating. If you add a new mesh, you need to make sure you have a TGA for the CK to find when generating the LOD.

Yeh thats what I tought , just not sure if needed ot be dds or tga ...