Teacher

You should complete your degree for a private job. For a job in government sector, you may have to take the test and need to follow the complete procedure.

In places like Mumbai, the teacher may get some payment, depending on the school. In the rural and semi-urban areas, the government jobs pay satisfactorily. But, the private jobs don't pay much.

Hello,
If you want to become a teacher, then you should go for B.Ed. But, if you are interested in professorship, then you should go for UGC NET.
UGC NET is the entrance test for the candidates who are willing to pursue their career further as a junior research fellow or an assistant professor.
You can refer to the link mentioned to check the eligibility criteria for UGC NET:
https://scoop.eduncle.com/ugc-net-exam-eligibility
I hope it helps.

For a regular teaching position, B.Tech is not the qualification for mathematics. You have to do PG in the same for the position of a teacher in mathematics.

Yes, your qualification is sufficient to be employed as teacher in government schools provided that you have cleared any entrance or eligibility test (if organised by that state or central government). I would suggest for further promotions or for high salaried teacher job pursue any master degree. Any specialisation in any particular field will also get weightage. Smart classes are now becoming integral part of our education system.

Good job. If you want to study further, opt for B.Ed. You can appear for S.I, BO exam.

Hello,
Yes, you can pursue B.Ed after completing B.Com in order to become a teacher.

The selection is made on the basis of a Test. Reservations are followed. The list is prepared on basis of merit. It is getting highly competitive, just like Police selection.