Dear aspirant
At first lots of congratulations for your results .

I can predict that your score is about 30-40 and rank is about 3-4 lakh. You have not mentioned that your are from which category. So I assume you as an general category candidate. According to trends of previous years and this year's JEE MAIN cut off I am afraid to inform you that your chances of getting admission into colleges NITs and IIITs are almost negative. However You can try in state level counselling and private colleges . But if you have any other category rank like ST , SC , OBC there may be chance for you .One thing is very important that admission in those above mentioned category entirey depends upon that particular category rank , not the All India rank.
you can check previous years cut off
https://engineering.careers360.com/articles/jee-main-cutoff-for-top-nits
check your chances here
https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer

Best wishes.