A rep for Paramount Pictures -- the studio behind 'MI:6' -- tells TMZ ... "Tom Cruise broke his ankle while performing a stunt. Production will go on hiatus while Tom makes a full recovery."

The rep goes on to say that the movie is still on schedule to be released next July.

As we reported ... Tom tried and failed the dubious stunt at least twice -- and one of those times apparently put him out of commission.

Get well soon, Tom.