There is no specific IB requirements for French universities, check individual university programs for requirements
Timeline for Parcoursup:
Research: November/December
International students (those who need a visa) register for une demande d'admission préalable (DAP) by 15 December.
Registering courses/wishes: January/February
Deadline to register: March
Non-Parcoursup applications (ESCP, ESSEC, EDHEC, Sciences Po and other private universities) - check each website for deadlines and application processes.
Presentation:
Higher Education options in France: slides here
Parcoursup: French PUBLIC university application system (for EU/Swiss nationals only)
Foreign students (non-EU or EEA who require a study permit in France) must apply for prior admission (DAP) to enroll in the first year of a bachelor's degree course at a French university. The DAP must be submitted before 15 December in Y13. More information HERE