Not nearly enough information.
Please post a new question with the coin's date and denomination. Also include any wording EXCEPT "Republique Francaise" or "Liberte, Egalite, Fraternite" - that will be on all French coins and doesn't help narrow down what it is.
the Sou (alternate spelling 'sol') was an old French coin.
'un sou' (alternative spelling 'sol') was a small French coin in the past. That still lives in the language in the expression 'avoir des sous' (to be rich).
FRANC
The old French coin starting with the letter "E" is called the Écu. It was a silver coin used in France from the 13th to the 18th century.
In French, 'huguenot' was the name for protestants. There is no old French coin known as a 'huguenot' - but there is a 1924 US half-dollar called 'Hugenot-Walloon tercentenary'. (follow link)
A franc
Old French coins would be called Francs. now the currency of money there is called Eros, but very old French coins were called Francs. Singular is Franc. Plural is Francs.
"monnaie ancienne"
It is an old French coin, from the 1940 to 1944 era.
The French currency in the 18th century was the franc. Some coins were named by old names like the Louis (the largest coin).
ecu
sou, ecu