Hello Aspirant

I dont think there is any specific department as such, which is best for getting recruited into ISRO. All the departments are equally weighed and considered.

But, according to me, a Bachelors degree in Aeronautical Engineering or Mechanical Engineering could be a good spotlight in helping you to have core knowledge and exposure even before taking up a career in ISRO.

You can also take electronics but you academics should be good and if you study these courses in Nits and IITs there will be a high chance of recruitment into ISRO with good academics.

If you have any questions further let me know.

Thank you!!!!!