After 12th
No you can not do it after 12th.
A programme in Apparel Management deals with the study of brand management, e-commerce, sourcing, product improvement, marketing tactics as well as operational management of textiles.The course curriculum comprises innovative technologies, leadership strategies, course work, field training, internships, etc.Apparel Management can be studied at masters level or as a postgraduate diploma or research.
For more information about this visit the below given link:
https://www.careers360.com/apparel-management-course
Good luck.