Watch this animation: https://pin.it/ml3c23hxu3alfh
Can this kind of lighting system be achieved in unity. I would like to have this kind of a light system in my pixel art isometric game. Not currently making one. But I will make one in future.
Yes it is definitely possible, you will however need to use colliders and a lot of layering.
You can combine assets such as 2DDL pro (link below) and regular lights (if you are using 3d objects for your world) or a combination of 2DDL lights if your world is completely 2D with fake 3d elements.
However Questions here should be more precise and I think you should start working on it and ask more specific questions about what areas stump you. As you can see, someone has already down voted your post because it is too vague.
2DDL