You can download JEE main answer key of any ship from official website of NTA. When you will enter your roll number then there will be the whole paper in which there will be the question options and the answer that you have taked and also the correct answer.

Or you can also download it from careers 360 I am giving the link here

https://engineering.careers360.com/articles/jee-main-answer-key/amp

Hope it helps.

To download the question paper, go to www.jeemain.nic.in (//www.jeemain.nic.in) . There you will find two separate links for " View question Paper " and " Challenge answer key ". Click on the first link and enter your credentials (app.no. and DOB or app.no. and Password). You will get your question paper along with the responses you made against each question.

To see the answer key, click on the second link, enter your credentials, and check the answers (given by NTA) for each question.

However if you feel strongly that a particular answer is incorrect then you can choose to challenge it to the NTA with the required information by paying a nominal fee of RS.1000/question.