As per a notice on the official website of JEE (Advanced) 2019, students with 40% or more disabilities will get an extra hour for each of the two papers of JEE advanced exam to be held on 27th May for entrance to the 23 IITs. Both the exams are held on the same day. Each paper is for 3 hours. The entire exam will be conducted in a fully computer based test mode. Registration will be open from May 3rd till May 9th. The extra time will be given to those students that fulfill a specified benchmark disability. The request has to be supported with propers documents at the time of registration. In case of any discrepancy/fraud discovered at a later date, his/her candidature will be cancelled for JEE (Advanced) 2019.

Source: https://www.hindustantimes.com/india-news/students-with-physical-disability-to-get-extra-time-in-iit-entrance-exam/story-LDva5Z7yyICQqQLzUOlX1H.html