Bihar

If you don't live in Bihar, then I think yes. I am providing you the following link so that you can check the locations of the study centres:
http://www.nalandaopenuniversity.com/admission.html

Since you have completed your schooling from a different state, you will have to submit a domicile certificate for WBJEE.

The basic eligibility for admission to MA in Mass Communication is a Bachelor degree in any stream of minimum 3 years duration. It is not compulsory to have a Bachelor degree in Journalism or Mass communication but it certainly gives an edge.
There is no restriction with respect to stream of education in graduation. However, certain universities do not accept application from students who belong to Engineering or Medical streams.

Yes, if you qualify JEE Advanced with good rank.

Yes, you can take admission in college of commerce, Patna even with your 10+2 Bio stream. You must have scored aggregate of 45%. Also, you must have learned English as one of the primary subjects.

Hi,
Top civil mechanical engineering colleges in Bihar:-
1) MIT Art, Design and Technology University
2) MIT Art, Design and Technology University
3) Manav Rachna International University (Engineering)
4) SANSKRITI UNIVERSITY
5) Dronacharya Group of Institutions
Hope this help.

Yes bro, you can get admission in this college easily.

Hello,
I hope you are doing well. Your friend need to go for state level counselling for particular state or go for state CET by giving the exam to get admission in that particular state colleges. There are around 20 % seats opted for other state candidates to get admission. Go for counselling your friend have OBC category he will get good college.