Commerce

Yes, you can get admission in FYJC commerce. If you have one year of gap, you can put gap certificate there. Your SSC marks will not take much importance or no importance. You can apply for admission there.

You can pursue BCA and MCA later.

First, complete class 12th, and go for CA. And, also you can go for CA after B.Com.

Yes, You can do MBA. It will be good for you.

If accountancy is your flavour, the CA and CWA are good, but if you wish to become a company secretary, then CS is good. You can also offer your consultancy services.

A professional course in mass communication opens doors for a career in films & TV, publishing, public relations, journalism, editing, direction, filmmaking, scriptwriting, production, etc. Depending upon personal interest and inclination a mass communication professional can choose a job. So you can join mass media.

If your sister is good in studies then she should try for CS after 12th or else there are many different options such as B.Com, BBA, BCA, BBM, B.Com and LL.B.

You need to qualify 10+2 with science for pursuing B.Sc in anthropology. As a commerce student I don't think you can do any technical course in science field.