IIM A or ISB Hyderabad? Which one should I choose now that I have got a call from both of these schools?

Academics are brilliant at both of these institutes. They both follow case study pedagogy. But they are different from each other in many ways.

Here are some differences between them to help you find a better match for your PGPM-

1. IIM Ahmedabad is much older, and has a rich legacy. ISB Hyderabad is comparatively new. 
2. ISB follows the European model of 1 year PGPM. IIMA offers 2 year PGPM, and 1 year PGPX. 
3. Even though the fee of PGP is higher at ISB, the course duration is lower at this college. This makes the short term ROI similar for both.
4. ISB requires a minimum 2 year work experience from its applicants. On the other hand, freshers comprise over 25% of a PGPM batch at IIMA. 
5. The average work experience of an ISB PGPM batch is around 4.7 years, the same for an IIMA PGPM batch is less than 2 years. 
6. Recruiters at IIMA seek candidates with a strong academic and extra-curricular record, but low work-experience. This is especially true for marketing firms, which are the biggest recruiters at IIMA. Thus, you might face difficulty in finding roles suited to your profile and experience at IIMA. But in this case, you may consider the PGPX program offered by IIM Ahmedabad. 
7. IIMA PGPM and PGPX courses record higher average salaries as compared to ISB. But this can be explained by the much higher student intake of ISB.

I would recommend you choose the college that best suits your profile and career goals. Both of these business schools are highly renowned and good in their own way. 

If you are a fresher, you should choose IIM Ahmedabad. It is the best B-School in the country and has a legacy of offering quality education in the management sector for over 60 years. At IIM A you will be among brilliant folks. The ROI is excellent. IIM Ahmedabad placements are the best in class. For 2022, the average package for the institute was INR 26.13 LPA. 

But if you have more than 4 years of experience, ISB is a better option. Most students of ISB have industry experience, so the peer-to-peer learning opportunities are good. The student crowd is diverse, you will get to meet people from all walks of life. The diverse student crowd makes the MBA experience, enriching. ISB placements 2022 witnessed an average CTC of INR 34.07 LPA.