Science

The candidate needs to have 50% in 10+2 with science for B.Sc+B.Ed.

I do not think if is there any distance learning university that offers M.Sc in chemistry or biology in online mode. These courses are available from regular colleges only. You can do some medical certificate courses in online mode but a degree course in Chemistry or Bio is not possible. Still, you can check this link to get more info about distance learning university and distance learning courses:
https://www.distancelearning.edu.in/

Considering you as a general category, if your overall 12th marks are below 60% but your aggregate PCM marks are above 60% (along with individual pass marks in each subject) then it doesn't matter since the eligibility criteria for Jadavpur University depend upon your PCM marks and pass marks in English.

Yes dear, you can very well give this exam next year but first focus on your class 12th marks.

Admission is based on 12th score. The better you score, the better college will open for you.

Hi,
Please specify the course that you are referring to.