What does Rollover mean?

Rollover or rolling over a contract means carrying forward the futures position by switching from the current-month contract closer to expiration to another-month contract with expiry in another month. A rollover is done by closing the position in a contract that is about to expire and opening a similar new position in another month's contract. Rollover can only be done for futures and not for options.

Example Scenario

1. A Nifty futures contract is bought with an expiry date of 23rd February.
2. The trader thinks that nifty will continue to go up in March and wants to hold this position till then.
3. Since this position will expire on 23rd February, the trader can exit the Nifty February futures contract and take a new position for March futures contract with an expiry date in March.

As per SEBI (ZIP), Rollover of contracts in the ban period is not allowed. However, exiting the existing positions is allowed. To learn more, see Why do F&O contracts enter ban period?