It's from Youtube show Screen Rant where movie producer has just heard about his cameo in a film and has got so excited. In response for that he says "I am tight". I don't have a clue what it means https://youtu.be/Zk_YKmtOYyI?t=68 1:10
When you are excited in anticipation you hold your muscles clenched. Imagine a child who is waiting for a birthday present. The child grips the chair, smiles in a fixed grin, presses their knees together. It is a natural response.
That is what the guy means. But it is a joke, you wouldn't naturally talk that way. The joke is that the guy is "tight with excitement". Despite being a movie executive, he talks like a teenager or a child.
Looking at some other videos in the same series, it seems that "tight" is a word that the "Exec" uses a lot. This kind of odd speech pattern is part of the comedian building a character. He tends to say "tight" when other people might say "smart" or "cool" or "excited". That is also part of the comedy.