I'm assuming you mean SWINGING French 5' patio doors and not SLIDING French 5' patio doors. There are two common rough opening widths: 5'0" or 5'2-3/4". Here's why:

Many manufacturers make a so-called 5' French door in which the rough opening is exactly 5'0" wide - but that means that the opening is 5'0", the door frame is approx. 4'11-1/4" and the doors are about 2'4" each.

The other way it's done is to have true 2'6" doors. So doing the math, the two 2'6" doors equal 5'0", plus another 1-1/2" for the frame, plus usually 1/2" or so for the astragal (it can vary), plus about 3/4" for the rough opening spacing = a rough opening of 5'2-3/4".

Again it can vary by an inch or so with some manufacturers.

As for the height, it also varies by manufacturer, but the common R.O. heights usually tend to be 6'8-1/2" (which is a shorter retrofit height for existing aluminum patio doors), 6'10" to 6'10-1/2" (these are the most common), and 8' to 8'2".