Avionics Eligibility

I have the same ambition as yours. Just go for aeronautical engineering (but remember that the vacancies are very few that is in single digits only) from any IIT or if you work hard then it might be possible you can get IISER or IISC-Bangalore. These are the students who get placements in ISRO, DRDO, etc. They do not have to work hard their course curriculum are relatively same as needed by the organisation. Now, if you are unable to get it, don't worry there is always another door open for you. You can go for B.Tech from any branch except civil and CSE. Then after completing your graduation you just need to appear for the exams conducted by ISRO every year.