Introduction
After researching the available platforms and concluding on the nRF51822, the choice of the firmware had to be researched.
Candidate RTOS with 6loWPAN support
Nordics SDK
RIOT
CONTIKI

Contiki port for nRF51822 does not handle the radio, so this one was eliminated

Then the Nordic's sdk have a binary blob for the radio and a special non free clause in the license.

The RIOT seems to be the only Free and Open Source rtos that seems to support the platform, their is even reference in the nordics blog for the nrf52.

The RIOT documentation is unclear if the radio of nRF51 is suppoted or not .

Following the RIOT instructions for nRF51822 lead to a working system without radio.

Tried flashing riot after flashing softradio and investigated how the Nordic sdk was loaded to memory.

Then when ahead and compiled and flashed the IoT SDK from Nordic specifically the CoAP Server Examples. those required a softradio that was not production ready and will never be according to Nordic.

I manged to ping the device over ble with the linklocal ipv6 that matched its Mac addresses.

The latency reported by ping was 100ms no mater the distance between of the radios.