I am not familiar with the specialization in which you want to do your MBA. Comparing BIMTECH and IMU is not justified, it is like comparing apples with oranges.

IMU offers two MBA programs: 

• MBA in Port and Shipping Management 
• MBA in International Transportation and Logistics Management.

BIMTECH offers PGDM (equivalent to MBA) programs in the following streams –

• Retail Management
• International Business (Human Resource, Operations and Decision Science, Finance, Marketing)
• PGDM Core ( Human Resource, Operations and Decision Science, Finance, Marketing)
• Insurance Business Management

I believe that you must first decide your interest in specialization and then proceed with the choice of colleges.