What should i bring as a gift to my uncle in thanksgiving?

That is very nice of your uncle to invite you for Thanksgiving and buy your plane tickets as well. What I would suggest is something small. Whatever state you live in, you can bring them T shirts with your state logo, or any souvenir item, like a mug or something like that. I am sure your uncle is not expecting anything, because his focus is to see you and your family. Again, I think a small souvenir item from your state would be fine.