Hello Rose,
As two months is not sufficient to understand each and every topic in concise manner. But there are no option except this.
See as per my opinion, if you have good command over the numerical portion like FTFM, then go ahead for Banking.
Else choose IPR or IBL.
See, case study will be noteasy for any of the subject, but you may refer CHARTERED SECRETARY JOURNAL as well as THE MANAGEMENT ACCOUNTANT journal for case laws.
Case Study can be solved easily if you have good command over the concept, try to read more and more.
Clarify your concept and try to understand each and every topic in practical manner. You may go for IPR.. As the cases of IPR is so much interesting (as per my opinion/ i like that cases).
Choice is yours! All the best for your exam.
Thanks