B.Ed

For distance B.Ed a candidate must have passed Bachelor's degree with at least 45% from a recognised university. Some of the best colleges which you can try for admission are given below:
Andhra University School of Distance Education, Visakhapatnam, Andhra Pradesh
Annamalai University Directorate of Distance Education
Bangalore University Directorate of Correspondence Courses and Distance Education
Bharathiar University-School of Distance Education
Bharathidasan University-Center for Distance Education.

Please mention the name of the college where you wish to apply.

I don't think so that there is any such option of choosing an additional paper. You need to follow the course structure given by the university.

As per NCTE norms, regular teachers working in primary, middle, secondary or higher secondary schools in Tamilnadu, recognized by State / Central government, with a minimum of two years teaching experience are only eligible for admission into Annamalai University Distance Education B.Ed course.

Please refer to the link to know about the important dates: http://www.dsvv.ac.in/admissions/important-dates/.

The paper is offline. You need to fill in the center code while filling the form. The question paper is both in English as well as in Hindi. So, you can request the invigilator to provide you with the Hindi paper during the exam.

There is a programme B.Ed in biological Science and for that you need to have completed graduation (B.A. / B.Sc. / B.Com. ), from a recognised university. A minimum aggregate score of 50% (45% for SC/ST candidates) at the level of graduation.