IIT

No, you do not have a chance. It would be better if you try for GFTIs.

Hi,
Please refer this link to understand what are the courses that are being provided by IITs in India. It will help you make the right choice for your studies.
https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.shiksha.com/b-tech/articles/iit-courses-blogId-19985&ved=2ahUKEwicxtaX9PnhAhUCbn0KHRPnAe8QFjALegQIAhAB&usg=AOvVaw2R33kMShNSyMcxXYPFmR1W.

Refer to the link below:
https://www.shiksha.com/b-tech/ranking/top-engineering-colleges-in-india/44-2-0-0-0.

Hello Sunanda,
It is not possible to get admission into IITs based on the JEE Main scores. Only after clearing JEE Advanced, you can get an admission. With Mains score, you can apply for NITs, IIITs and other colleges.

By taking biology as an optional subject.

It depends on your class and also, on your preparation time. If you are in class 8th then it will cost less compared to your class 12th preparation. But in general, the fees would be in the range on 90,000 to 2,00,000 INR in Delhi.

Click on the link below and check which all colleges you can get:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor.

See, getting in to reputed IITs and NITs is based on the marks and percentile you have scored in this JEE Mains 2019 paper, on that basis, only any one can predict the chances.

Hi,
Please visit Shiksha.com's college predictor-
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor. Ranks keeps on changing every year and differs from one branch to another and one college to another. If you fulfill the eligibility criteria of the specific institute, you may complete further admission formalities. For now, I would suggest you to first contact the institute officials of the shortlisted universities directly for specific eligibility criteria details.

Hi,
Please visit Shiksha.com's college predictor-
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor. Ranks keeps on changing every year and differs from one branch to another and one college to another. If you fulfill the eligibility criteria of the specific institute, you may complete further admission formalities. For now, I would suggest you to first contact the institute officials of the shortlisted universities directly for specific eligibility criteria details.