My view is that six months is still a good time even for self study for both the groups. Since you are familiar with second group, you are much more in a good position. Do not plan for Nov 18 and devise your plan. Fix the target as May 18 and re-work the plan. Its better to have that "push" factor.
Also, self study is very much possible for First Group. Very little value will be added by attending classes for Law or Auditing and with continous practice you can always score well in FR and SFM through self study.
Thanks and Regards
Sathish