Hello Aspirant!
I'm providing you below the admission procedure for Institute of Forensic Science (IFS), Mumbai, Maharashtra as you have not specifically mentioned the college name.

Government IFS (Mumbai) is affiliated to Mumbai University, established by the Department of Higher and Technical Education of the State Govt. of Maharashtra in 2009.
B.Sc. in Forensic Science is a 3 yrs duration undergraduate course. The basic eligibility criteria for this course is qualifying (10+2) level with Biology or Life Sciences as one of the subjects with minimum 50% marks. Your Class 12th aggregate percentage is considered usually for granting admission. Admission to B.Sc. Forensic Science is provided in IFS (Mumbai) by online mode only.
As per the previous year admission guidelines, the first step is to mandatorily fill the pre-admission online Enrolment form of Mumbai University available on the website :
www.mum.digitaluniversity.in
The process of registration and online admission form usually starts in the last week of May. But this year, due to COVID-19 pandemic, there is likely to be certain changes in the schedules.
The prospectus and other necessary instructions related to admission are released at : www.instforensicscimumbai.in
or links from 'News & Updates' of www.ifscmumbai.com

The websites I've mentioned above are not working well currently as they are under construction or maybe due to nationwide lockdown. Recent admission guidelines will be provided soon. Once the sites are functional, you need to first enrol yourself as mentioned,  then register and fill up the online application form for the institute by uploading all the required documents. At the end, you need to pay the application fees online. List of selected candidates will be released later on the official website.

Please keep visiting the sites periodically by the first week of May to stay updated.

Feel free to ask in the comment section if you have any more queries.

Hope this answer will help you.