Commerce

You can pursue B.Com, BBA or BBM after completing class 12th.

Absolutely he can. Ask your brother to take up an entrance examination from which he can get an admission to colleges with those examinations.
I came across this examination called as university-GAUGE which has partnered with many universities.
For more information, visit: https://goo.gl/Wsokpv

No, you can not. B.Ed is compulsory to qualify SET.

Hi Silpa,
It depends whether you want to pursue B.Des or B.F.Tech programme. To apply for the B. Des programme, there is no requirement of Mathematics but For B.F.Tech programme, candidates should have passed in 10+2 qualifying examination with physics, chemistry and mathematics as main subjects from a recognized state or national board of education.

The option Commerce + Hindi would be fine, when one is weak in computers. And, if you don't have interest in the same field. Also, this option can be highly scoring (provided you are not good in computers of course).
There are several options to choose after Commerce + Computer. If you are good in computers, (then it will increase your overall score also) and if you are interested in this field.

It's up to you. You need to know area of interest and your aim and in which field you want to make your career. You have number of options to choose among, like if you get good percentage, somewhere around more than 85% marks, then my, suggestion is, you should go for regular college in DU, and after that you can go for MBA through CAT/XAT.
Or,
You can go for professional courses such as CA/computer science/ICWA along with graduation from correspondence.

In 1994-95, Osmania University has granted affiliation for M.Com degree, and Government of Andhra Pradesh has approved the same. The admission into M.Com course is through a common entrance examination conducted by Osmania University every year. The Management has provided a separate PG Block with all amenities. The sanctioned strength is 40.

Almost, all cities in India have open universities or institutions that offer M.Phil through distance learning. The pioneer is Indira Gandhi National Open University (IGNOU). This university has study centers in almost every state in India. Each of these universities conduct their own admission or entrance examination.