CBSE 12th

Your score is pretty good for admission in both SIESCOMS and NL Dalmia. If you want to do PGDM in Finance, NL Dalmia is a better option and if you want marketing then go for SIESCOMS.

Only students from Maharashtra can apply for MHCET. But there is another option you can apply for KCET as well as JEE through which you can apply for colleges throughout India.

First B.Sc. Nursing
BBA.

Date of commencement of Online Application- 1st week of April 2018
Last Date to fill Online Application- 2nd week of May 2018
Admit Card Issued- 3rd week of May 2018
Date of Entrance Exam- 1st week of June 2018 (2:00 pm to 5:00 pm)
Result Publication Date- 2nd week of June 2018
Online Counselling Starts- 2nd week of June 2018

Yes you are eligible, only thing is you have to know is your percentile score. The actual percentage is not the same as percentile. Like in CBSE if anyone has scored 82 percent then his percentile score is somewhere in 70's. In Bihar board 80+ percent means 90+ percentile. So you can give your Mains. Just don't worry. Work hard and achieve your dreams.

You should have technical knowledge, knowledge of using Linux and programming knowledge. It would be better to join any engineering college if you are interested and simultaneously join any online or offline course whatever you are comfortable with and enjoy hacking but in an ethical way.

No, you are only eligible after you clear your intermediate, i.e. class 12th.

B.Sc. With it will be good.

BBA or B.Com or mam 5 years course.