Hey.
If you have completed your Undergraduation in BSC Zoology and now want to pursue the field of law, you can go for a 3 year law degree First and then do a diploma or LLM in Intellectual Property and Patent Law.
Most of the Institutes offering diplomas in Patent/ IPR Law have a requirement of a 3 year/5 year Law degree atleast. And as far as LLM degree is concerned LLB degree or equivalent is compulsory to be eligible.
Best of luck!