Hii,

The Indian space research organisation (ISRO) recruits students only when there is a vacancy in job roles.Always check the official website for the vacancy posts.It doesn't matter about the branch.you can have jobs with respect to your  department.ISRO needs every engineer in its growth.

You must complete your Btech /B.E / Mtech get a job in ISRO.You better get admission in IIST  rather than doing engineering in foreign countries.you will have high chances of recruitment from ISRO.

One of the best option to enter into ISRO is get admission in IIST for btech / mtech and do graduation in whatever the branch it offers.If there is any placement ,you will get a job  in ISRO.

If you didn't get admission in IIST,Do graduation degree BTech/B.E and give ICRB exam for scientist/engineer in your stream.After that perform well in the interview and get a job in ISRO.

All the Best...,