Hello Dear aspirant

There is a good scope in the government sector after B.tech.You can opt for the Indian Engineering services (IES) ,  you can get a job in various government organizations like the one in DRDO.
You can prepare for Competitive exams like UPSC or Railways,  you can get a Job in the Banking sector.
You can try to get a job in PSUs.
For a more detailed answer,  visit the following link....
https://www.careers360.com/question-list-of-government-jobs-exams-after-btech