Hindu College, University of Delhi

Hi,
Hindu college is one of the best colleges of Delhi University and for taking admission there, you need to get at least 95%, if you are from general category.

Zoology cutoff of Hindu college reaches 94% for general and not less than 83% for SC/ST. So, it is not possible to get Zoology with 54.33% marks.

No special preparations are required as such. Delhi University does not conduct any exam for B.Sc Chemistry. Class 12th marks are used in for admission in the university.

I'm really sorry but there is no course available at the University Of Delhi which offers you seats in 57%. Kids scoring 75% are unable to grab a seat. It will be great if you try somewhere else.

Yes, you are eligible. Eligibility for admission to B.A(Hons.) in economics is students who have passed in mathematics at the Class XII level.

There are multiple books available and they all are good. You can start with for quantitative ability:
1. Arun Sharma published by Tata McGraw Hill.
2. The Arun Sharma Complete CAT Digest by Tata McGraw Hill.
3. Quantitative Aptitude for Competitive Examinations by Abhijit Guha.
4. Quantitative Aptit

It's necessary that you should have economics and maths in 11th & 12th for doing economics honors

Depends on the course you are opting for. There are chances that you may get admission through vacant seats or in the last cut-offs.