costas charalambous

Hi my Freelander1 2006 would not start and the battery went dead as it had been sitting for a while so I fully charged the battery and tried to start it but it would not start ? I called AA and they said I needed a new transponder ring "after using his eobd obd gadget" which said immobilizer error? so I got a new one and the car still did not start . Is this a programing issue ? and how can I reprogram the key fob to my car ? Thanks anyone?