[satya_37@ip-10-0-0-213 bin]$ splunk reload deploy-server
-bash: splunk: command not found
The message indicates your shell doesn't know where splunk is on your system. Try
$SPLUNK_HOME/bin/splunk reload deploy-server
or
/opt/splunk/bin/splunk reload deploy-server
and consider adding /opt/splunk/bin
to your PATH.
Specifying the path like this should work for you. Also, it looks like you are already in the bin directory, in which case you just need to prepend a ./ in front of the command to tell it to look in the current directory for the splunk command. Try:
./splunk reload deploy-server