What are the major differences between BA in mass communication and BJMC (Bachelor's in journalism and mass comm.)?

Hello, There is no difference between both the courses. It's just only the nomenclature of course. Few universities and campus give BA (JMC) degree and few one give BJMC and GJUS&T, Hisar provides B.Sc degree in journalism and mass communication.

Both are same. There is no difference.

Mass Communication is an umbrella under which you have fields like fields such as advertising, event management, public relations, and also journalism. So, in B.J. M. C. you are taught Journalism in detail which includes - Print, digital, tv and radio medium.