To change the retry count for an OTA update from the CLI, pass the parameter --block_retry_max=N (that’s two dashes at the beginning) to the “xbee” CLI command, where N is the requested max retries per image block. 
(For example, xbee --block_retry_max=25 fw_update target updater /WEB/mesh/filename.ota).
Note that the --block_retry_max parameter must be immediately after “xbee”. 
This max must be 0-255, anything else will return an error; 0 will use the default, but anything less than the default will use the default instead. 
(The “default” happens to be 5 for XB3 and 6 for S2C.)

If you use RCI to perform OTA updates at all, the same parameter can be passed as an attribute on the <fw_update> node.
For example, <do_command target=”xbee”><fw_update target=”…” file=”…” block_retry_max=”25” /></do_command>.
When this parameter is given and non-zero, a message “Using block_retry_max value of …” will appear in xbee.log, so that you (and we) know a non-default value was requested.