What is the name of the biggest sat in the universe?

Answer 1

One of the biggest stars that we can observe and measure is Betelgeuse. This star is fairly close to us.

No one can see even a tiny tiny bit's worth of the total universe, though, so in that sense, there can be no answer to your question. Remember . . . galaxies contain billions of stars and the universe must contain billions and trillion of galaxies, nearly all of which we cannot 'see'.

Answer 2

I think you spelled something wrong. The question makes no sense.