Dear charumathi,
I would like to clear your doubt. Yes you can give UPSC Examination.
They have mentioned that Candidates must hold a graduation degree in any stream from any university.
So your BSc degree will be considered.
Also UPSC Examination mentioned following eligibility criterias-

1. candidate must be a citizen of India
2. Candidates must be minimum 21 years and maximum 32 years of age as on August 1, 2020

i hope this information helps you

all the best