Hi @Gopi_N,
I hope you are doing well.
i.MX8MP supports up to 8GB DDR memory space. One can refer to Table 4 i.MX 8M Plus modules list on Page 10 of the datasheet.
NXP doesn't recommend any specific memory vendor. However, one can refer to the EVK design files for reference.
Thanks & Regards,
Ritesh M Patel