I need to set GMT +1 timezone for the logs. Please let me know what would be the value set in TZ=? in props.conf.
If there is no other way, you can force a particular TZ but it's best if the source either reports in UTC or provides timezone spec within the timestamp. Otherwise you might run into some unexpected issues when daylight saving kicks in.
Go to https://www.timeanddate.com/time/zones/ and choose any time zone with an offset of "UTC +1". "CET" looks like a good choice.