I'm pretty sure that they are fully compatible with the C RDI version.
IIRC there is a procedure to mount this tanks in the 2000C/B RDI ground crew manual, maybe with specific code for armement panel, but I'm not sure.
Furthermore, in the real aircraft threre is no fuel quantity measuring for the drop tanks. The ground crew or the pilot set the "totalisateur" manualy before the flight. So if you set 5.8t instead of 6.2t it should work without problems.