Dear candidate if you really fond of computers, programming languages, circuits and devices then go for CSE otherwise Avionics at IIST is a great course. You will receive guidance from ISRO Scientists to help you build your career. The Faculties are extremely qualified, all the necessary facilities for Avionics course is there. Coming to placements, if you score a good CGPA you can receive placements in ISRO,DRDO and some other prestigious places.

https://www.careers360.com/university/indian-institute-of-space-science-and-technology-thiruvananthapuram

Good luck!!