In JEE Advance if You score more than 35% marks then Your name will be included in the rank lists, However in Past there were instance s that the cutoff marks went down significantly, Perhaps 2016 was the years when cutoff went down to its all-time low of 20 %, anyways if You score more than 35% marks then Your name will be definitely Included in the rank lists. But making it to the rank list does not Guarantees IIT, It is Your All India Rank on which basis You are allocated seats.