Hello Chitresh,

To get IIITs or NITs you need to first clear the required cutoff as per your category in JEE Mains. For GEN-EWS category, the 2019 JEE Main cutoff was 78.21 percentile. Since, you have got less than 78 perecntile so you are not JEE Main qualified. Now you can aplly for counselling through JoSAA, but cannot get seat in the first few rounds. However in the later or last round of counselling you might be able to get a seat in NITs or IIITs. So better you attend the JoSAA counselling session and see which colleges and branches are you getting on the basis of your rank. 

You can go through this link and checkout the details regarding JoSAA counselling : https://engineering.careers360.com/articles/josaa-counselling

Good Luck !!!!!