Hi,

M.Sc microbiology is a two year post graduation course. It's full form is master of science in microbiology. Usually post graduation courses or masters courses are done after completing the graduation. Yoy can not apply for M.Sc microbiology after 12th.

So you need to do B.Sc in biological sciences or microbiology  then you can apply to M.Sc microbiology.

Few institutions provide integrated B.Sc -M.Sc course which one can do after 12th. So you can opt for that.

Hope you find it helpful.