Babasaheb Bhimrao Ambedkar University (BBAU), Lucknow

First, you have to graduate and yes, you are eligible after the completion of your graduation because graduation in any subject can apply for Master's degree in library science.
Good luck.

Basic eligibility to apply for M.Sc. in Forensic Science and Criminology at Babasaheb Bhimrao Ambedkar University, Lucknow is that candidate should have completed their graduation and Must have completed graduation in any discipline of Life Sciences/Medical Science/ or other allied subjects like Phy

Every university has its own entrance or take students through CAT or MAT.

The minimum percentage required for B.Tech or BBA admission is 50% and above. Some colleges keep the cut-off as 60%.

Refer to the link for details:
https://www.shiksha.com/university/babasaheb-bhimrao-ambedkar-university-lucknow-26165/admission#admission

You need to apply online and thereafter you need to appear for the entrance test conducted by the Babasaheb Bhimrao Ambedkar University. Admission is through counseling based on the marks obtained in Entrance Test.

Hi Satyendra,
The website has not mentioned anything for their academic calendar. It is advisable to get in touch with the college officials for more clarification on this.
Regards.

In this paper, they will ask for your high school syllabus based MCQs. So, if you study your high school syllabus, you can easily clear that test.
Good luck.