Hello aspirant according to jee mains percentile 2019 you are eligible  for jee advance 2019 as the cutoff releases by nta for General category is 89.56 percentile        General ews category 78.21 percentile

But you also need to get minimum 75 percent in your 12 exam to give jee advance and for admission in nits or iiits 

For more information visit this link :

https://www.google.com/amp/s/engineering.careers360.com/articles/new-eligibility-criteria-for-nits-and-iiits-admission-says-mhrd/amp