Hello,

Technical assistant is a job offeres by isro to the candidates who have done b.sc. And applications for same is released by isro you need to grab oppurtunity whenever it comes.

Mostly b.tech students offered scientist positions in isro where entrance exam is conducted followed by personal interview.

You need to do msc first in order to apply for various recruitment in isro.one thing you should keep in mind that academic performance is also one of the parameter taken into consideration so you have to secure as much percentage as you can otherwise it is difficult for you to get into isro.

Visit link to know about recruitment process

https://engineering.careers360.com/articles/isro-recruitment/amp

Good luck for future!!