CONFIG_CPU_R6000 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips
default or selected kernelversion does not have config value CONFIG_CPU_R6000.
Result is shown for kernelversion 6.5.1

R6000

modulename: r6000_fpu.ko

configname: CONFIG_CPU_R6000

CPU type
└─>R6000
In linux kernel since version 2.6.12  
MIPS Technologies R6000 and R6000A series processors. Note these
processors are extremely rare and the support for them is incomplete.

source code: