Can I do a job with B.Tech?

Yes, you can but for the you have to take admission in average college for that because top and good colleges of engineering doesn't allow you to do job along with the education as you have to attend the college compulsorily. If you can match up your college time and job time then you can go for it.

Yes, you can. There are a lot of companies as well as government sectors, which require B.Tech students.