Trouble on object

hi i'm newbie using unity and my object looks dark and bright parts. Anyone know what can it be? https://postimg.cc/S265TLTp

 

Your attempt to post an image didn't work, so it's hard to say. But if I had to guess, I'd say you have a strong directional light in the scene, and only weak ambient light. You can adjust that in the Light Settings window.

 

in the post, the image link so you can see it.

 

OK. I have no idea what's going on with that. Where'd you get that model?

 

create the model in rhinoceros 4.0

 

Is this mesh double sided?

I suspect, there may be issue with normals, some are set facing up, some may be facing down.
You would need try to reset normals, to see, if that is the case.

 

How can I restore normal values?

 

Best if you do that in the software that mesh has been created.
You could use blender as well. There are tons of tutorials available.