which is the best field in m pharmacy related to biology
There are some specialisations in M.pharmacy which is related to biology:
M.Pharmacy in Biotechnology
M.pharmacy in pharmacology
M.pharmacy in Medicinal and natural products
M.pharmacy in phytopharmaceuticals and natural products
As you are interested in biology field , you can choose any of the above specialisation as interest matters then only you can perform better in that particular stream.
Best Wishes