From which field I should do b-tech to get a nice job in ISRO?

ISRO takes Direct recruits from Indian Institute of Space Science and Technology(ISAT) you can apply for its entrance. Other than that There is a back door apply for some good IIT's, NIT's, VIT ,LPU etc where defense forces recruit for technical cadre, ME,EEE,ECE,CS,IT are usual branches they select

Dear Avinash, You need to have completed your B Tech or BE in the streams like electronics, electrical, computer science or mechanical engineering. You need to have aggregate score of 60% and above throughout your career. The candidate can appear in the written test during the final year of B Tech

You are recommended to do engineering is Aerospace Engineering to increase your chance of working in ISRO. Indian Institute of Space Science and Technology, an autonomous institute under Department of Space, Govt. of India is the best Institute for Aerospace Engineering. Institute conducts B Tech in