According to the Splunk documentation1, the _indextime field is the time when Splunk indexed the event. This field can be used to confirm duplicate event issues from failed file monitoring, as it can show you when each duplicate event was indexed and if they have different _indextime values. You can use the Search Job Inspector to inspect the search job that returns the duplicate events and check the _indextime field for each event2. The other options are false because:

The _time field is the time extracted from the event data, not the time when Splunk indexed the event. This field may not reflect the actual indexing time, especially if the event data has a different time zone or format than the Splunk server1.

The _index_latest field is not a valid Splunk internal field, as it does not exist in the Splunk documentation or the Splunk data model3.

The latest field is a field that represents the latest time bound of a search, not the time when Splunk indexed the event. This field is used to specify the time range of a search, along with the earliest field4.