If you meet the eligibility criteria for the Common Entrance Test (CET) of JBIMS and achieve a score above the required cutoff, there is no need to worry about your admission chances. The admission decision is based solely on the score obtained on the written test.
However, once admitted, you will likely be asked about any gaps in your education during various stages, such as while preparing for summer internships, during summer internship interviews (for companies that have a no-gap criterion), while preparing for final placements, during final placement interviews, and even during your first few job changes. JBIMS may be accepting of a 99.9+ score, but recruiters may not share the same enthusiasm.
You may be asked about any gaps in your education during the interview process. In this case, it is important to share any relevant experiences and learnings from the gap year. Having a gap in education is not a problem, but not having learned anything from it may be viewed negatively.
It is too early to worry about these potential scenarios. Focus on preparing for and performing well in the written tests, as the rest can be managed later.