NIOS is a recognized board in India just like any other board such as CBSE or CISCE. You can find the list of Indian universities and State boards that accepts NIOS certificates after 10th Std. for their courses at http://www.nios.ac.in/media/documents/listofuniv.pdf and http://www.nios.ac.in/media/documents/listofboards.pdf
Because Islamic subjects can be taught under NIOS only and the same provision is not available under CBSE or ICSE.
As the curriculum includes both Academics as well as Islamic studies, so as per the rule of the Government we have to mention Maktab.
Students can appear in the board examination either from NIOS or State Board under the form 17 scheme.
For Arabic language syllabus of Ummul Qura, University of Makkahtul Mukarramah will be followed and for Islamic studies (English) syllabus of Jamia-Islamia, Madina University will be followed.
InshaAllah Extra classes of Hifz will be started from 1st Std. (most probably early morning before the 1st period) depending upon the capability of the student.
Quran and Authentic Hadeeth.
Excursions, Class activities, Taekwondo (from 1st Std.), Annual Sports, EPS (English Public Speaking), APS (Arabic Public Speaking) etc.