hello mam, can you tell me if I am eligible for a msc in bio chemistry or in microbiology?
as I am not doing a major in zoology or botany or chemistry so am i eligible for the above options ?

You should have bsc with marks in total in chem, biochem, botany, zoology, microbiology and other life sciences.
If you donot have the graduation degree in above subjects then the admission process shall become a bit tough.
Also Some universities take an entrance for this course like Nirma University and Amity.
You can check what criteria IGNOU follows.