Hello,

If you want to go for Indian Air force and CDS then you can choose any department of engineering.

But I'll suggest you that you can take mechanical engineering stream or computer engineering stream. This two are best for your in future job. You can learn lots of things which is required for your future. And for your new job you can learn from staring also but you can know about something in your graduation level also. So you can choose between this two stream in BTech.

All the best.