is st joseph university darjeeling economics department good?

I think you are asking about the Economics course at bachelor level. The college provide admission to BA in economics, the department is good but there are no job placement or other facilities provided you can visit the website and find the same. Department is good, there are few more colleges which provide admission in Darjeeling for economics is Darjeeling govt college, north Bengal college etc. You can take if it near you place, but you must even see the review and enquire from existing students about the course further.