Hello @ancymuhammed,
Just for double check, could you please check your NOR Flash's hardware connections and the NOR Flash's clock?
Also, could you please verify you have the proper boot configuration to communicate with your external memory? In the MIMXRT1170 EVK Board Hardware User's Guide and MIMXRT1170HDUG Hardware Development Guide for the MIMXRT1160/1170 Processor you could find information related with the Boot mode configurations:

[MIMXRT1170 EVK Board Hardware User's Guide. Section 2.2. Boot mode configurations]

[MIMXRT1170HDUG Hardware Development Guide for the MIMXRT1160/1170 Processor. Chapter 6. Boot, reset and miscellaneous]
Best regards, Raul.