"When coolant was still green, or blue"
G11 is the oldest type of coolant mentioned. G11 is usually blue (sometimes green) and contains silicates. Silicates are salts. This means that the product is only suitable for cast iron engine blocks. If you use it in engine blocks with aluminum heads/water pumps/radiator parts, it is corrosive. Something that Triumph Stag riders, for example, paid their tuition with.
"Modern Red or yellow"
G12 came later when aluminum engines/heads became common. This fluid is red, sometimes yellow. Unlike G11, G12 is based on Organic Acid Technology (OAT). This means, among other things, that G12 does not contain silicates, so it is not harmful to aluminum parts. In addition, G12 contains improved additives that protect the cooling system. In 2005, G12 received an update: G12+. The improvement came from a package of better balanced additives. G12+ is purple or colorless and is also called universal coolant. The stuff mixes well with other coolants, an action that is generally not recommended. And then there is also an upgraded G12+, the G12++, also called G13 for convenience."
So I'm going for the G12, yellow variant, as the Billancourt and Cleon engine has a cast iron block with aluminum heads.
And never mix coolant variants, just flush the whole system and make sure to use one type of coolant,
Renault recommended to change every 3 years or 45.000 kilometers, but the nowadays longlife types of coolant may last longer.