The Robot was made in Blender and rigged in blender too. The only animation it has just a Standard Walk and nothing more. In each folder you'll get 2 files one which is rigged known as FINAL and the other one which is only a model known as ONLY ROBOT. If you don't like my Rig or want to rig it by yourself you can use ONLY MODEL to do that. There is just only 2 textures and I think that would be enough. You can see animation preview on my youtube channel.I'll suggest to use blender since its a native file of blender and blender is free. you can BLEND file in your Blender and rig or export it However you want.CHECK OUT MY OTHER MODELS and HAVE A NICE DAY....
BLEND (Blender, filesize: 62.1 MB), OBJ (OBJ, filesize: 17.5 MB), FBX (Autodesk FBX, filesize: 51.8 MB), GLTF (glTF, filesize: 51 MB), ABC (Alembic, filesize: 23.2 MB), DAE (Collada, filesize: 32 MB), PLY (Ply, filesize: 18.9 MB), STL (Stereolithography, filesize: 19.1 MB), TEXTURES (Textures, filesize: 16.9 MB), USD (USD, filesize: 8.03 MB)