Hello,
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That's good on your part that you have passed 12th with good grades.
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There are many under graduate Courses in fashion designing to choose after 12th and some of them are,

• Diploma in interior design
• Master of design
• Bachelor of fine arts
• Bachelor of design (leather design, accessories designing, knitwear design,BSC footwear)
• B.Des fashion designing etc,

There are even other fields to choose like fashion designing diploma and certificate courses like,

• Diploma
• PGD
• UG diploma
• Advance diploma
• Certification

These are some of them you can choose after 12th.
If you are looking for more value then persue masters if not you can enter job field.
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Thank you
Best of luck