I'm studying in 12th and interested in fashion designing. What should i choose among fashion designing and engineering?

Do that in which you have your interest and you think are capable of doing better than the other field. Follow your passion and yes fashion designing also gives job opportunities with good salary packages, sometimes even more than an engineer's package.

Go with your passion. Convince your parents and make them understand the importance and value of fashion designing in today's world. Make sure, you keep up your word and achieve something.