The answer is dependent on your level of interest.
The scenario at IIM Lucknow PGP-ABM is as follows:
Many PGP ABM students prefer FMCG firms for Sales/Marketing positions.
In short, you will almost certainly receive a higher salary at IIM Lucknow, but it may not be in an agribusiness/development sector organization.
The IRMA Scenario:
For example, UNICEF, Tata Trusts (FISE), Vedanta Foundation, Reliance Foundation, and BAIF Development Research Foundation.
If you are very specific about agribusiness or rural development roles, you should apply to IRMA because of the large batch size and the increased number of Agri-specific roles coming to the campus. If you want to explore other sectors or domains and are looking for a brand name for life as well as a higher package, i.e. an experience similar to that of a PGP student, then IIM Lucknow is the place to be.