There is no braille designation for the okina and there is not even agreement about representing it in print. It usually resembles an apostrophe, but that is not what it IS. Sometimes it is printed as an apostrophe, sometimes as an opening single quote. It is also referred to in different ways, sometimes as inverse comma or reversed apostrophe.
The recommendation for braille is to use uncontracted braille, as in any foreign language, use the 456 preceding the affected letter for the macron, which is an established braille usage, and use the dot 4 accent indicator for the okina, again preceding the affected letter. List these in special symbols and just identify the dot 4 as okina (glottal stop). If there is a letter with both an okina and a macron, I would follow print order, okina first, followed by the macron, followed by the letter.
--Joanna