It's not a standard phrase. I need to know the lines that come first.

Traditionally, drinking tequila involves salt, and a lime. (By "lime" I mean the sour, acid, green citrus fruit). You have salt on your hand. You lick the salt. You drink a sip of tequila. Then you suck the lime.

Tequila also traditionally has a maguey worm in the bottom of the bottle. Perhaps that is just a myth.

I suspect they are talking about limes, salt, or possibly worms.

"Why do you have a lime in your refrigerator?"

"That's for tequilas."

Another possibility is that you didn't hear the words correctly.

which movie did you hear it in? What is the context?

Maybe "THAT'S FOR TEQUILAS" mean "That's ridiculous" in fact? For example "Don't be ridiculous" or "He doesn't know this ridiculous man"?