JEE Main Eligibility

It is upto cut-off of this year. So, you have to wait for the result announcement and cut-off declaration. Only then, you come to know you are eligible or not. But as you said, you have been attempted 260 marks question according to me you should be eligible if you have been attended atleast 150 marks right question.
Best of luck.

Please visit this site
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor.

Yes, you can give Mains 3 times and Advanced 2 times.

75% is enough for the eligibility but issue is meeting other criteria too.

Kindly visit this link:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor

Kindly visit this link:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor

General rule for most of the board for reappear for 12th examination will be taken in the same I.e. if you have appeared in March you have to reappear in March only. So, you cannot appear for July. Please check with your state board office of concerned state.

You should prepare for colleges like DTU and NSIT.
For more information, you can visit this link:
https://www.shiksha.com/b-tech/jac-delhi-admissions-exam

As per your category, if your rank is less than 1,00,000 (general rank), then you will get some branches in DTU and NSIT. However, HBIT is taking admission via JEE Mains from this year, so we cannot predict the exact cutoff.

Enter your rank in the link given below and get the list of best colleges, if AAT is in the list, you can be sure of admission
https://www.shiksha.com/b-tech/resources/jee-mains-branch-predictor
Hope this helps. All the best for your admission.