Funds are unblocked after shares are allotted. The mandate for IPO applications is usually revoked after allotment. Upon revocation, funds will be unblocked in your bank account. As shown below, the mandate request has a specific end date.
Note: Some banks may wait until the end date of a mandate to complete a revocation. You can check the end date of a mandate on your UPI app. In case you did not receive an allotment of shares, you can request your bank to release funds at any time post-allotment. Upstox is not responsible for your IPO amount release because as a broker we only provide a platform to apply in IPO.