You can write $host command on powershell prompt to check powershell version or you can execute the below T-SQL script to check the powershell version.

declare @regkeyval varchar(20), @value varchar(255), @rc int
exec @rc=master.dbo.xp_regread 
  @rootkey= 'HKEY_LOCAL_MACHINE',
  @key='SOFTWARE\Microsoft\PowerShell\1\PowerShellEngine',
  @value_name='PowerShellVersion',
  @regkeyval=@value output


set @value =isnull(@value,'-') 

if @value <> '-'
select 
 @@servername as SQLInstanceName
,case serverproperty('IsClustered') when 1 then cast(serverproperty('computernamephysicalnetbios') as varchar)
 else cast(serverproperty('machinename') as varchar)
 end as WindowsServerName
,@value as PSClientVersion 
,'PS is installed' as PSStatusCheck 
else
insert into #OUTPUT(SQLInstanceName,WindowsServerName,PSStatusCheck)
select 
 @@servername as SQLInstanceName
,case serverproperty('IsClustered') when 1 then cast(serverproperty('computernamephysicalnetbios') as varchar)
 else cast(serverproperty('machinename') as varchar)
 end as WindowsServerName
,'PS nt installed' as PSStatusCheck