There are different solutions for the SEP Manager and SEP Client.

SEP Client
To view the install type of a client, open the SEP Client GUI.
Go to 'Help', 'Troubleshooting' and chose 'Install Settings'.

If you want to perfom a registry query, please find below the corresponding registry keys:
[HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\Symantec Endpoint Protection]

Standard client
"ReducedSize"=dword:00000000
"DarkNetwork"=dword:00000000

Dark Network Client
"ReducedSize"=dword:00000000
"DarkNetwork"=dword:00000001

Embedded / VDI Clients
"ReducedSize"=dword:00000001
"DarkNetwork"=dword:00000000

SEP Manager

To view the install types of the clients on the SEP Manager, you can find the types

a) in the client properties.

b) in the 'Clients' tab, 'Tasks' > Search Clients.

   In the 'Search Field' select 'Install Type', select a 'Comparision Operator' and as 'Value' the corresponding install type.

c) by running a database query.

The following example displays the client name, SEP version, client install type, operating system, user name etc:

Query:

SELECT DISTINCT
    "SEM_CLIENT"."COMPUTER_NAME" "Computer Name"
  , "SEM_AGENT"."AGENT_VERSION" "SEP Version"
  , "SEM_AGENT"."INSTALL_TYPE" "Client Install Type"
  , "SEM_COMPUTER"."OPERATION_SYSTEM" "Operation System"
  , "SEM_CLIENT"."USER_NAME" "User Name"
  , "IP_ADDR1_TEXT" "IP Address"
  , "IDENTITY_MAP"."NAME" "Group Name"
  , "PATTERN"."VERSION" "AV Revision"
  , dateadd(s,convert(bigint,"SEM_AGENT"."CREATION_TIME")/1000,'01-01-1970 00:00:00') CREATION_DTTM
  , dateadd(s,convert(bigint,"SEM_AGENT"."LAST_UPDATE_TIME")/1000,'01-01-1970 00:00:00') "Last Update Time"
  , "SEM_AGENT"."DELETED" "Marked for deletion"
FROM (((("SEM_AGENT" "SEM_AGENT" INNER JOIN "SEM_CLIENT" "SEM_CLIENT"
  ON (("SEM_AGENT"."COMPUTER_ID"="SEM_CLIENT"."COMPUTER_ID")
  AND ("SEM_AGENT"."DOMAIN_ID"="SEM_CLIENT"."DOMAIN_ID"))
  AND ("SEM_AGENT"."GROUP_ID"="SEM_CLIENT"."GROUP_ID")) INNER JOIN "SEM_COMPUTER" "SEM_COMPUTER"
  ON (("SEM_AGENT"."COMPUTER_ID"="SEM_COMPUTER"."COMPUTER_ID")
  AND ("SEM_AGENT"."DOMAIN_ID"="SEM_COMPUTER"."DOMAIN_ID"))
  AND ("SEM_AGENT"."DELETED"="SEM_COMPUTER"."DELETED")) INNER JOIN "PATTERN" "PATTERN"
  ON "SEM_AGENT"."PATTERN_IDX"="PATTERN"."PATTERN_IDX") INNER JOIN "IDENTITY_MAP" "IDENTITY_MAP"
  ON "SEM_CLIENT"."GROUP_ID"="IDENTITY_MAP"."ID") INNER JOIN "V_SEM_COMPUTER" "V_SEM_COMPUTER"
  ON "SEM_COMPUTER"."COMPUTER_ID"="V_SEM_COMPUTER"."COMPUTER_ID"
  AND "SEM_AGENT"."DELETED"=0
ORDER BY "Computer Name"

Output:

Client Install Types:

0 – Standard Client
1 – Embedded Client
2 – Dark Network Client