Hello

I am here to help you with your query.

https://engineering.careers360.com/articles/nata-eligibility-criteria

You need min 75 % in 12th standard.

Your rank now depends on the score you get in the exams. 

For more queries do comment below.

Good luck

Hello!! 

The cutoff ranka vary from category to category ans changes from year to year. So mention you category, quota and home state to get detailed information about your query.

Go through below links for more details.

https://engineering.careers360.com/articles/jee-main-cutoff/amp

Best of Luck!!