Hello KR Singh,
the ways explained above are not sure shot ways to confirm if the system installed is single or dual stack.
HTTP Service can exist without J2EE as it did in older versions of SAP , same goes for the parameters (if they aren't configured properly).
The best way to check this is at the OS level.
Else you can do the following:
Check and validate the presence of J2EE schema in your database via transaction DB02
And combine this check with checking the presence of jlaunch and java processes in transaction ST06->Detailed Analysis->Top processes
Hope that helps.