Hello aspirant 

After B.pharmacy you will be able to start a drug store a and you will be a graduated person..
But if you want only start a drug store then you do a D.pharmcy (Diploma ) which Is sufficient to start a Drug store
There are some legal formalities to open a drug store . (1)1st of all you will be registered pharmacist in the state pharmacy council..
(2) then fill the form no. 20 A to application for opening a drug store.
(3) Then 2 separate form applied ..One for biological drugs and other for non - biological drugs with there fees

Hope you understand,
Thank you