B.Ed

Yes, you can teach commerce in schools. Choosing education and mathematics in B.Ed doesn't matter for that. But you must have knowledge in the subject of commerce for teaching commerce in schools.

You apply for B.Ed but before counselling and admission, your result must be cleared.
If not cleared, then you can't take admission.

Hi Preet,
Please specify the university name for better clarification. Every college is different and hence admission process and eligibility criteria varies accordingly.
Regards.

Hi,
Eligibility Criteria:
Candidate should have Graduate and a Bachelor's degree obtained through the 10+2+3 system or an equivalent qualification with a minimum aggregate of 50% or equivalent CGPA of any of the Universities incorporated by an act of the central or state legislature in India. A Relaxation of 5% aggregate is there for SC/ST candidates.
The webpage of this college is silent about fees charged for various courses. You can get in touch with the college officials for the detailed information on the fee structure.
Regards.

Yes, you can easily get a teaching job.