Hello aspirant,

Step - 1: Complete 10+2 or equivalent exam with PCM stream from a recognised Board

Step - 2: After completion of 12 th study B.E/ B.Tech in Mechanical Engineering, Aeronautical Engineering, Radio Engineering, Electrical Engineering, Aerospace Engineering, Engineering Physics or any other relevant stream from a Popular Institutions like IIT, IISc, NITs, IIST or any Premier Institutions by craking JEE Mains, JEE Advanced entrance exams.

Or can pass ISRO Centralized Recruitment Board after completion of B.E/ B.Tech with minimum 65 percentage.

Or Study Masters or Ph.D in Engineering.

Step - 3: Appear for ISRO exams as per the eligibility criteria if you meet.

Similar process with NASA.

Visit below given link to know how to join ISRO after 12 th standard.

https://www.careers360.com/careers/articles/how-to-join-isro-after-12th-counar

I hope this information will help you.

Good Luck!!