The six men aged 32 to 38 are suspected of helping to finance jihadi networks that recruit young people to fight in Syria.
All six appeared together in a French court today to face preliminary charges and were ordered held without bail. They were arrested Sunday in the city of Toulouse and town of Albi in southern France.
Police have conducted several anti-terror operations following last month's terrorist attacks in and near Paris.
They say Sunday's arrests were not linked to those attacks.