The National Testing Agency has uploaded the Answer Key for JEE Mains 2019 candidates to challenge. Candidates can visit https://jeemain.nic.in and click on Challenge Answer Key and then login with their credentials to proceed.
This facility is available from 15 Jan 2019 to 17 Jan 2019 (till 11:50 PM) only.
The Candidates are required to pay online a sum of Rs. 1000/- as processing fee for each question challenged. However, the processing fee will be refunded if the challenge is found correct.
Please check here for more details:https://jeemain.nic.in/WebInfo/Handler/FileHandler.ashx?i=File&ii=21&iii=Y