No, there is no special lock-in for gold bought via SIP, you can sell it at your convenience. However, for your safety - we enforce some set of rules which prevents selling for digital gold worth more than Rs.50 for the first 24 hours. These are valid during normal digital gold purchases as well.
Please note that indiagold reserves the right to remove/update all running offers (if any) on your SIP without prior information. Please talk to customer support for more details.