In my opinion ISB is better than Oxford on the following fronts:
1. Investment in Rs and salary in Rs. - Average package is going higher every year.
2. ISB is able to provide job to a large batch in India in a campus interview kind of atmosphere.
3. Job scenario for outsiders in UK is pretty bad. I have seen some oxford MBA grads searching for job in India. Searching for job in Rs after doing an MBA in pounds is a scary situation to be in.
Emory in comparison to ISB is better:
1. US has varied job opportunities, with Emory you would be getting less salaries in comparison to the schools you may get with better efforts.
2. Post Emory if you don't get a job in US you may still target an internal transfer to locations like Canada, Dubai, or possibly Europe in case you don't get an H1B Visa.
Only downside to Emory is a big investment but another way to look at it is the amount of salary you will be losing out by working one more year in India versus what you would make by working in US. But again that is a short term perspective. A better MBA school a year later may be more rewarding in long term. But then hard work can overcome the gap between top 20 MBA vs top 50 MBA. Top 10 MBA vs Top 20 MBA. HSW is another matter.
Decide based on long term or short term goals.... Lot of factors riding together mate....