Hi Jatin,
CBSE will release the official JEE Main Answer Key on April 24, 2018. You will be able to access the answer key in online mode. However, you can download the answer key released by various coaching institutes.
Various leading coaching institutes like Resonance, FITJEE, Allen Kota, Sri Chaitanya, Aakash, etc. have released the JEE Main 2018 answer key.
You can download the answer key from the given link:
https://engineering.careers360.com/articles/jee-main-answer-key
Good Luck!!
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