Hi Pratyush,
I’m no expert in this field, but I believe one could either use a standard SD card interface IP block, which would almost certainly require the use of the Zynq processor to handle the complexity, or just use a plain SPI serial interface, which could either be via the Zynq processor or via a stand-alone SPI IP block directly on the RTL fabric.
Here’s a link on the Digilent forum which gives some ideas on how one might go about it.
If you prefer a stand-alone SPI Master IP block, this Tech Forum post provides an example one might follow.
Additionally, this Tech Forum post discusses how one might establish an SPI interface between an FPGA and an external MCU, including a CRC check to verify data integrity, which might also give you a few ideas.