Hey Ganesh, 

You might get a seat through your obc quota in a nit. I am giving you a link which has opening and closing rank of nit for year 2018 go through it and find a suitable option for yourself 

Link:

 https://www.google.co.in/url?sa=i&source=web&cd=&ved=2ahUKEwiW9sCijuviAhXLvY8KHQg5CeUQzPwBegQIARAC&url=https%3A%2F%2Fgradeup.co%2Fjee-main-cut-off-i&psig=AOvVaw15f7XLT9TyA9K5l6YmQSbU&ust=1560675187413395

All the best!