I assume that you have both options IIM Ahmedabad PGP-FABM and XLRI HRM. If that is the case, then you should make a well-informed decision based on your personal inclinations.

If you had taken Agricultural Engineering because you were genuinely interested in it, then IIM Ahmedabad, PGP-FABM is the best choice for you. 

However, if you had to take Agricultural Engineering because that was the last option you had, then it makes no sense to continue with it. In that case, XLRI HRM is the best option for you. This is because the job opportunities after FABM, are scarce, and you. HRM will fetch you office jobs.

Brand-wise both institutes are similar with IIMA having the upper hand. Placements-wise, HRM is better unless you have an interest in Agricultural Engineering.