CA

No, there is need of any approval from any institute.

You really need to work hard after MPC. Take coaching. Read books available in the market. I will personally recommend you to go through online interviews of CAs.

Yes, of course. You can see many people who have opted for CA after MPC. Just move on.

Yes, it's better to get CA after 10+2.

Hi. Any graduation can be done. Even, you can go without graduation for pursuing CA Course. Generally, Bachelors degree in Commerce is preferable.

You can do both CA as well as B.Com at same time.

its all are professional courses with b.com. CA And CS both is valuable course market has both demands. cs is comparatively easy than CA.

Yes, you can. There are no restrictions on that behalf
As long as you have a Bachelor's degree, or have professional working experience that totals up to 4 years.

We all know that CA is the toughest exams. So, I sincerely suggest you that, yes, it's possible to do a job and pursue CA simultaneously.

It's better you take B.Com first and then MBA because for CA you need to study maths as much as possible, if you took maths in +1, and +2, you could have taken CA as you can easily pursue CA with some basics from 11th and 12th but, you didn't then go for B.Com. You can have a better experience through that. I think you should pursue what you desire.