Hello Navya,

To become drug inspector, exam is conducted by Union Public Service Commission known as UPSC and also various state PSCs and Staff Selection committees on an annual basis named Drug Inspector. 

For this candidate needs to have bachelor degree in medicine or in science or in pharmacy with 45% with any PCI recognised university. And candidate must have 18 months experience in testing or manufacturing to become drug inspector. 

All the best. Hope this will help you.