Is it mandatory to pledge my MTF funded stock? 

As per regulations, CDSL authorisation is mandatory for MTF, and therefore shares must be pledged at CDSL for MTF trades to be processed and for broker funding.
The purchased shares remain in the demat account of the client but are marked as “pledged” in favor of Jainam.
At Jainam, CDSL authorisation is auto-completed by T-day for those MTF trades on which funding is provided. The client is not required to take any action from their side to complete the MTF pledge process.