yes definetly you are elegible to write the JEE advanced as qualifying mark in JEE mains is about 50 percentile only so you qualified and your are an NGO so you will have a better reservation too in the NGO quota so you can join in any NIT or else you can definetly write JEE advanced and get a seat in IIT so ano need to worry about it , hope you get agood seat in IIT and all the best for your future