Discs as in brake discs?
If you've bought the discs and they're the correct ones for your car then there is no need to worry about the centre part which sits over the hub.
The only bolts that secure the disc to the hub are torx bolts (T35 from memory).
The centre nut secures the hub to the axle and does not need removing.
Disc > Hub > Axle
Lol, why the hell didn't you just say that!? Talk about beating around the bush!
Well the centre bore on a Clio is 60.1mm from memory.