Hey there,

B.voc in marketing management and retail business is a good course given you're studying it from college of vocational studies, Delhi University. Initially, the pay scale is average and the amount is same as others. If you want to change the course, it depends on your percentage in 12th grade you have to check the cut offs and migration structure in your college. See if you're eligible or not, if you can migrate or not because all colleges in Delhi University have started taking classes already. 
You can try next year too, it you'd like. 
The things you can do after this course are highly associated to marketing sector, you'd be eligible for jobs in brand management, store operation, retail marketing, visual merchandise, HR management, digital marketing