Hello Mitali Mone,
Eligibility for Bachelor of Science [BSc]

Candidates must obtain 50%-60% aggregate marks in 10+2 examination with Mathematics as oneofthe subjects.

Usually, the universities require only the best 4 subject marks to be included in the 50%-60% criteria, but mathematics must be one of those subjects.

Hello aspirant,
I am here for helping you.
As you got 50.62% in your class 10+2 and you want to do plane B.Sc so , you may be eligible for this because for doing plane  B.Sc you must score at least 50-60 percent marks in your class 10+2  and this percentage basically vary with college to college as for some colleges it is 50 percent and for some it reaches to 60 percent so, for some college you are eligible to apply for plane B.Sc  but you may defeat for some colleges .
I hope it will be beneficial for you.......
For more queries you can upvote my answer and can ask in the comment section below.....
Best of luck....