Hello himanshu,
I agree with nisha suggestion ,as she said 70 days time is sufficient for a single group.Many students who are in job or doing articleship takes a month leave and clear exams.So in your case,it is not short span of time.Secondly,the strategy of above 60 marks in two subjects and 40-50 marks in other subjects is also a good plan.You can choose from F.M/Accounts & Company law.Audit Paper is always a tough one because it require practical exposure and skills on the basis of which u will get good marks.However,it totally depends on your vision whether to score high marks in theory or practical subjects.
All the best!!