You are an employee in a French company. Two types of statuses may apply to you.
You can be "seconded" if you meet the following conditions :
If you meet these conditions, your social security coverage will be the same as if you stayed in France.
French law (Article R 761.1 of the Social Security Code) has set the maximum duration of "secondment" at 3 years, renewable once (i.e. a total of 6 years) for countries that have not signed a social security agreement with France.
However, for the countries of the European Economic Area, and Switzerland, Community rules provide for a maximum "secondment" period of one year, renewable once, except in the case of exceptional secondment.
With regard to these exceptional secondments, it can be added that in some cases they can reach 5 years or more. Your employer must make a request to CLEISS (Centre des Liaisons Européennes et Internationales de Sécurité Sociale).
Some non-EEA countries have signed a Social Security Convention with France which also provides for a maximum period of "secondment" : Algeria, Andorra, Benin, Bosnia and Herzegovina, Cameroon, Canada, Cape Verde, Chile, Congo, Côte d'Ivoire, Croatia, Gabon, Guernsey, Israel, Jersey, Macedonia, Madagascar, Mali, Mauritania, Morocco, Monaco, Niger, New Caledonia, Philippines, Poland, French Polynesia, Quebec, Rep. Czech Republic, Federal Republic of Yugoslavia, Romania, San Marino, Senegal, Slovakia, Slovenia, Togo, Tunisia, Turkey.