Assuming it is a typo and you are asking for the "Stratum" value, take a look at e.g. http://kb.vmware.com/kb/1005092
st: Stratum is a value representing the hierarchy of the upstream NTP servers. Higher values indicate NTP servers further away from the root time source. Values are relative, and can be set manually by an NTP server.
The value will vary depending on how far from the time source it is.
A ESXi host would always be stratum 2 or higher, because its is network linked to a stratum 1 device. If it gets its time directly from the stratum 1 device (e.g. a GPS clock or similar), then it would be stratum 2. If it gets it from another server (most common) it would likely be stratum 3.
As i know startum 1 computers are not GPS Clocks they are the time servers so how it can directly sync it from time server even they can get the time from locally attached device?
Stratum 1 devices ARE the GPS clocks:
The basic definition of a stratum-1 time server is that it be directly linked (not over a network path) to a reliable source of UTC time such as GPS, WWV, or CDMA transmissions.
Check this out that's saying something else:-
While NTP (depending on what version of NTP protocol in use) supports up to 256 strata, only the first 16 are employed and any device at Stratum 16 is considered to be unsynchronized.
Here is main link:-
Well, given that the ESXi host is not a cesium clock, its not stratum 0. Given that its not directly connected to a cesium clock, its not stratum 1. That only leave it to be a stratum 2 or higher.