Hi Goutam!
NTA has released a notification on the official website today which says that candidates can claim a refund of the duplicate fee after the May session. As per the JEE Main 2021 exam scheme, a candidate could apply for one or all sessions together or separately. And if you do not appear for any session then the registration fee will be adjusted to the fee of next attempt.
Hope I answered your query, thankyou!
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