B.Ed

The BEd course is for 2 years everywhere in India, and if you're opting for an integrated course, then it is for four years. The same is the case in Bihar, and the seats are filled by the Bihar BEd CET or BEET. 

From the above 2 mentioned books, R gupta is one of the best books for preparation of BEd Entrance. 

Candidates preparing for the Bihar B.Ed CET exam should attempt the mock tests regularly when the exam is close by 7-10 days. These Bihar BEd CET mock tests help candidates to get a quick insight into their preparation level. Additionally, it will also helps to them enhance the speed and accuracy for the examination.

The passing marks for the Bihar CET BEd. exam are 35% for unreserved (UR) candidates and 30% for reserved category candidates (SC, ST, BC, EBC, WBC, and PH). These percentages translate to 42 marks out of 120 for UR candidates and 36 marks for reserved category candidates, The candidates can find the complete details in the released cut-off Bihar BEd CET exam list. 

The Bihar BEd CET (Combined Entrance Test) is a 120-mark exam, with each question carrying one mark. There is no negative marking.

Yes, Commerce students can definitely do B.Ed and become teachers too if they completed their graduation (like B.Com.) with at least 50 - 55% marks.
Now, when it comes to teaching, you will usually be eligible to teach subjects like:

Commerce or Business Studies
Accountancy
Economics (in some cases)
Maths (if you had it in 12th and graduation)
Keep in mind that you will have to pick subjects during B.Ed that align with what you studied. Also, if you plan to teach in schools like CBSE or state boards then clearing CTET or state TET with commerce-relevant subjects will make your journey smoother.