Heyy Pratisksha....

Yes , you do have an excellent chances that you'll get into some reputed NITs as you have  got 83.94 percentile but your category will also matter in the process of admission. For the final cutoff you'll have to wait till 30th April as it will be declared along with the result of the second exam. Also if you perform better in the next exam of April, then the chances of yours increases further. Also if you want you xacuse this formula to calculate your rank of Jan exam : 

JEE Main 2019 rank (probable) = (100- NTA percentile score ) X 874469 /100