Hi pal,
B. Sc  biotech is 3 years ug course in india.the entrance exams for addmission depands upon universities.university like delhi university is one of the best education platform for biotech,it's addmission procedure based on marit cutoff of 12th percentage.there are some exams for ug biotech.
1.AIIMS biotech entrance test.
2.jnu combined biotech entrance test.
3.CBEEE(combined biotechnology entrance examination)
Hope this will help you.
Good luck.