Reading the OS guide for CX 10.xx it does appear that RADSEC is supported.
However, reading the datasheet for CX6100 and CX6000 RADSEC is not mentioned (it is mentioned in the CX6200 datasheet)
However, even in the CX6200 datasheet it is only mentioned in commentary section and NOT in the table of supported RFCs.
Can anyone please provide a definitive answer?