If you don't want to go for the IBS Ahmedabad then you can get admitted to the IBS Dehradun. There is no such mandatory thing to go for IBS Ahmedabad if its get cleared.

Both the business schools you have mentioned are quite good & there won't be much of a difference from the perspective of scope & career ahead.

For more information regarding IBS Dehradun you can consider the link below:

https://www.careers360.com/colleges/ibs-business-school-dehradun

For more information regarding IBS Ahmedabad you can consider link below:

https://www.careers360.com/colleges/ibs-business-school-ahmedabad

I hope this helps. Wish you a great eve!