Shaily,

If you've have a attested domicile certificate issued by the principal of your school, or any gazetted officer or any MP, MLA (this may not be valid too because most of the cases they approve income certificate, not domicile) then you're eligible for Delhi region quota. Without that piece of paper it's not possible to apply with it. You can find sample of Domicile certificates from here: https://wbjeeb.in/UploadDoc/Docs/WBJEE/101_1002_126_765799.PDF

Regards