Hello candidate,
Hope you are doing well,

Yes, definitely you can apply for Msc. in Biotechnology after completing graduation in Zoology. Those who have completed graduation in any biological subjects are eligible to apply for the exam. The degree must be passed from a recognized educational institution with a minimum of 50% marks.
Biotechnology is Master of Science in Biotechnology is a two years Post Graduation Course and can be pursed after Graduation from Science stream. The eligible candidate must be an Indian national having completed Graduation with Botany, Zoology and Chemistry/Agriculture etc.
Here is a website for you :

https://www.careers360.com/courses/msc-in-biotechnology

Hope this will help you
Thank you!!!