A science (pcb) student is eligible for doing graduation in fashion designing course or not?

Yes, not only a science student any other student who have completed 10th standard are eligible for doing graduation in fashion designing course. Even after completion of b tech you can join for fashion designing course. If we want advance certification it nearly takes 1-2 years.

Hey Esha,
Yes, ofcourse you can do graduation in Fashion designing course. As the eligibility criteria for Fashion Designing course says that,

• A candidate must have passed 10+2 examinations from a recognized school or board in any stream.
• A candidate must have scored minimum 50% marks in aggregate in the qualifying examination.
• The candidate must have minimum 17 years of age and maximum 23 years of age for admission to this course.

So, it really don't matters if you are from Science Stream, you are perfectly eligible if you fulfill the above criterias. Go ahead!
Good Luck!