I have no idea about after 12.Iam very interested in mathematics and chemistry .so which is best course for me to get a good job.
you can opt for engineering , basically chemical engineering, keeping in mind your interest for chemistry and mathematics. you can also opt for BSC in mathematics or chemistry and after that go for MSC.
with the job perspective you can go for,
BBA, BCOM, ENGINEERING.
It's sounds good that you're interested in maths and chemistry,i would suggest you to go for bsc hons in mathematics or you can take bsc hons in chemistry from du or other university. That will give a new direction to your career . After bsc you're able to do Master's in any particular branche of Maths or chemistry.
Hope this will help you.
Good luck.