There's no such cutoff in india io pursue bsc forensic science. But some institutions such as amity or du conduct entrance exams for this. Rest, you can get admissions on the merit list. In general the criteria is 55%-50% in higher secondary. But the criteria may vary according to the College in which you want to take admissions. In Institute of Forensic Science , Mumbai, you need to have 85% marks for general category and 75%-70% marks for reserved category.