B.Com

You can get any government college in your state. You can pursue your M.Com there.

Graduation is required that is it, honors or not does not matter. All you need is good academic score and a high percentile in the entrance.

Yes, it's possible as lots of people do that. And there is a huge advantage as well because you will get good in maths in comparison to others.
Best wishes.

Yes, you can pursue B.Com. First, you have to fill the waiting list form. After getting the merit list, you all get your rank and further proceedings are not that difficult. You'll have to fill the online form and then carry required documents, a printout of the online application form and 12th mark sheet. Submit it the same in the college with fee structure. Make sure that you pay the fee via Net Banking, DD, Chalan, or Cash.

Yes, you can, but don't expect a very good college.
But if you work hard, you can easily compensate for that in placement.

You should complete all the stages of CA. CA final exam clearing is a headache for almost 90% of aspirant. Do join a coaching institute if you need professional coaching. Yes, you can prepare for CA along with B.Com course. Doon Business School, Dehradun offers CA+CPT coaching along with B.Com course. Good Luck.

There are basic entrance exams will be held like for GK, Basic maths, etc. So, all the best.

May I know your location?

Are you talking about Mumbai? If yes, there are many colleges such as KC College, VIVA College and SN College.