not able to apply patch 10390503 10390503:R12.FWK.B not able to apply : patch's intended release i

Hi,
not able to apply patch 10390503 10390503:R12.FWK.B   not able to apply : patch's intended release is "12.0.0"
The following error occurs :
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This patch is not compatible with your on-site release:


patch's intended release version and

on-site          release version

do not have identical major and minor version numbers (first two components)



patch's intended release is "12.0.0"

on-site          release is "12.1.3"

patch's intended release is "12.0.0"

on-site          release is "12.1.3"
------------------------------------


Patch name is  patch 10390503:R12.FWK.B so this means this is a R12.1.3 patch as its codline is B

Any ideas ?

Best Regards,
Eric.