All the films I have seen, made from 1961 and before, the stars like Yves Montand in the film Goodbye Again based on Francoise Sagan's novel; Aimez-vous Brahms. he calls the waiters garcons. Was this OK back in those days, though I know not now This old film is not translated. It's in English with Ingred Bergman and a sappy Anthony Perkins.
Great scenes of Paris, by the way.

No, make it M'sieur s'il vous plaît

Just try snapping your fingers and shouting, "BOY!" at a waiter in New York, and see what happens.

Or as my ex-husband did once to my eternal mortification: "Hey, Holmes!" (One of many reasons why he's the ex.)

I know it's not appropiate I know it's M'sieur but wondering if back is the 50s and 60 if that was used because it surprised me to hear Yves call Garcon to his table, Back at that time there was nothing called politically incorrect.

Unless the film wanted to show his character as thoughtlessly arrogant, even by the standards of those days?

A bit of googling turns up that the word is still in current use as a third party indication of the job itself. But my guess is that it might have depended on where you were eating as much as when, because there are a lot of references to "garçon de café". Might it never have been right in a Michelin-starred restaurant, but just about acceptable in a corner café if used to the obvious junior trainee (rather than the proprietor)?

There was a time when it was acceptable, and now it is not. Just like Mademoiselle or Fräulein was acceptable for addressing a young and presumably not-yet-married female who didn't display a wedding ring, or an older one that you knew not to be married. That was then, this is now.

And there are many more terms that fell out of favor. So address your waiter with M'sieur s'il vous plaît (the l in il is mute unless you mean to pronounce it rather pedantically - sounds more like "si vous plaît").

But with the professional waiters in France there are subtleties in communications that are perfectly ok if done right. For example, as the waiter goes by your table and you catch his eye, to point at your empty beerglass and nodding will get you another, whether the waiter stops to ask or not. Or to raise a finger when you catch his eye from a distance will make him swing by your table as soon as he's done with his current errand. Be subtle and polite - finger snapping and big arm waiving probably won't work too well.