if is it possible then which memory are use for store the hex file.
external flash or system flash?
please suggest other option also.
What is "FOTA"?
Firmware Over The Air
Basically remote firmware update.
Yes, stage the new firrmware somewhere in your design. If enough internal flash then use that.
its Firmware Over the Air
I would tend to use a binary packaging method, the .HEX type files are about 2.4x larger than necessary.
What is the "air" in your delivery strategy?
i will use LTE Module for that
So perhaps the easiest would be a binary file server via HTTP or FTP
Retrieving data ...