Hello aspirant,

Hope you are doing absolutely great.

So with regard to your query, for the marks between 70-80 you might get a rank of or above 40k and possibly as you belong to reservation category you might get seat in the colleges. The cutoffs generally vary from one year to another. You can predict your colleges from the college predictor link, and may also know your correct marks through the marks vs percentile link. I'm forwarding the two of them. Check it out.

College Predictor:

Marks vs percentile: https://engineering.careers360.com/articles/jee-main-marks-vs-percentile

Hope this helps you!!