There is no way to show SEP clients that are 32/64bit
If you select a client from the Clients page, it will give you the OS architecture.
However, 64bit SEP will only install on 64bit machines so some assumptions can be made.
You can also run a report if you go to Monitors page and set the Log type to Computer Status. It will also give you the OS architecture here as well in this report
You can also check here as only some SEP components are strictly 32bit even if installed on 64bit machine
https://www-secure.symantec.com/connect/forums/why-64bit-sep-installed-none-64bit-folder