Hello Alp Arslan, The default chimer setting is 3nodes that contact NTP servers.  Now you can change it from the default of 3 to 1 if you would like, as you will need to go to the chimer settings to do so.  Here is a link to the PowerScale OneFS Web Administration Guide & if you look on page 43 it explains about the NTP time server. [URL]
Please advise one of correct statement from Below. this statement confusing me a lot.  1. By default, If the cluster has more that three nodes, three of the nodes are selected as chimers.  2. If the cluster four nodes or less, only one node is selected as a chimer.
Chimers