Dear,
In order to become a fashion designer one should consider pursuing a bachelor's degree in design. Some popular courses that candidates can pursue in design to become a fashion designer are – BDes, BFTech, BSc in Fashion Design, Fashion Merchandising, etc.

Students who have cleared their Class 12 from any stream (Science/ Commerce/ Arts) can pursue a Fashion Design course at graduation level. However, most popular Design colleges allow  to take part in their admission process only if they have completed their schooling from a recognized board(You need to check that). For Fashion Designing at postgraduate level, students who have completed a Design course at graduation level are preferred for admission.

You can also pursue Fashion Design courses at the PG level like MDes, MFTech, and the likes. While hiring fashion designers, employers usually shortlist applicants who are creative and who possess good technical knowledge of how clothes, accessories, or footwear are produced.

Hope this helps!