Smdenton:
Being in Georgia the applicable code is the 2000 IBC. However, since GA is going through the adoption process, I'll focus on the 06 IBC.
And to answer the easy question, the provisions for what some call "pedestal construction" are found in section IBC 509. Your design conditions most closely fit IBC section 509.2, although I'm not sure how the design professional got out of the Type I construction, even if sprinklered.
If the below grade parking can be treated as an open parking garage, then it is classified as a Group S-2 open parking garage. If it is not open, it is classified as a enclosed parking garage. IBC section 903.2.9 requires sprinkler protection throughout the building. This portion of the system would be designed in accordance with NFPA 13 (see IBC 903.3.1.1).
I will assumne the parking garage is enclosed for the purpose of the analysis.
First floor: Group M/S/B occupancy is the most plausible occupancy classification. This would be designed in accordance with NFPA 13 for based on the hazard classification.
Floors 2 - 5: You are correct - the height limitation of NFPA 13R has been exceeded. So the residential dwelling compartment and corridor requirements of NFPA 13 would apply, as well as the provisions for attic sprinklers.