Sanjana28 .. Following the discussion among you,
LeoN88 and
GyanOne ...
I would like to suggest you below points:
1. Choose ISB when you want to settle down in India. You will carry a good brand name and reputation of ISB.
2. The mixed feedback from people is quite natural. You will not get a satisfaction level of 100% even from Top 10 MBA/Masters programs (remember point no. 1).
3. Consulting practices prefer young candidates or with high GMAT score. So, you will not be at any disadvantage of starting your career with candidates having 5 years of experience. People with less years of experience can be molded easier than the people who have huge years of experience.
4. St. Gallen is renowned in Europe. You should not face issue in getting an employment if you work in right direction from day one. The recruitment process is different for Europe than it in India.
5. Languages are not always an issue. In hiring process, you need to at least prove/show that you are currently learning and will be in fluent in future (does not apply to UK and somewhat to Netherlands/Scandinavian countries). If you show zero interest, nobody can help you.
6. St. Gallen will be bit risky but will be rewarding if you plan to settle in Europe.
To conclude, ISB would be better for you to start your career with the ISB's brand name.