Visit the link below for more details: 

http://www.barcouncilofindia.org/educational-criteria-educational-qualification-required-for-admission-into-3-year-and-5-year-law-courses-in-india/

Hi Gopal,

Yes, you can sit for BA LLB entrance exams after clearing your 12th from NIOS. Students passed out from NIOS board can write any professional body exam such as CLAT, BHU LLB etc and every university must accept students from open schooling.  “The Secondary/Sr.Secondary certificate obtained from NIOS have the same recognition as certificates issued by other Boards. NIOS is vested with the authority to conduct Public Examinations at Secondary and Sr. Secondary level vide Govt. of India's resolution dated 14 September 1990. NIOS thus acts as another National Board”.

Hello dear

You can go to this link to know about the courses available through NIOS - 

http://www.nios.ac.in/online-course-material/secondary-courses/admission-detail-for-various-courses.aspx

Hope this helps

Thanks!