Translate the following English sentence to French:
"What point is there in knowing which family members have the right to enter and reside in the EU, when it is not known what provisions are to be made for which immigrant groups and for which reasons for immigration?"
À quoi sert-il de savoir quels ressortissants bénéficient du droit d'entrée et de séjour dans l'UE si l'on ne connaît pas le mode de réglementation applicable à tel groupe d'immigrants ou à tel motif d'immigration ?