Ignoring the fact that this situation cannot arise as the number of students applying for examination will never fall below such minimum let me answer you query with quoting what Rishabh Jain(an AIR holder) has said in one of his answers .
"Let us start with what is the criteria to appear in merit merit list of ICAI (or be a rankholder in simple words).
ICAI recognizes meritorious candidates in Intermediate (IPC) and CA Final examination, by ranking them on the basis of the aggregate marks obtained by them in both the groups, on an all India basis, subject to his/her having secured a minimum of 55 percent marks, in one sitting without availing of any exemptions.
There is no practice of declaring any candidate as having secured a rank beyond 50 in Intermediate (IPC) or CA Final Examination.By above definition you need to fulfill following criteria to get a rank:
- Clear both groups at a time;
- Secure minimum 55% marks; and
- Get your score among top 50 scores to fulfilling above criteria.
So those of you who are planning to write you exams group by group or targeting that magical number of 50% are out of the race. Anything discussed below does not apply to you."
So here even if less than 50 students come to sit for the examinations and just pass them without going above 55% bracket no one will be covered in the merit list.