hi,

see cutoff score varies every year , depends on candidates category, difficulty level of exam, now coming to your score of 100 out of 300, according to previous years analysis your rank would be ranges from     46076 - 36253, so this is a approximate rank and have decent chances for securing nits. however nits have 85% seats reserve for domicile candidates and remaining 15% seats are fills by all india quota counselling. To know more about rank vs score do follow our article at below link:

https://engineering.careers360.com/articles/jee-main-marks-vs-rank#JEE-Main-Marks-vs-Ranks-2021