Do companies like Google, Microsoft and Oracle recruit students from B.Tech IT background?

Yes, they do, because as their main work is information technology they primarily visit various colleges during campus recruitment drives and pick the best students to work for their companies.

Yes, of course, companies like Google, Microsoft and Oracle recruits students from B.Tech IT background. These companies only recruit CS and IT students.

Yes, companies like Google, Microsoft, Oracle and other good IT companies recruit students from B.Tech IT background (only for CS/IT students). But you have to clear their recruitment process.