Hi Shikhar,
Case 1:
If the services that you are accessing are known to you , you will probably know the services that are published.
So , you can query them using urllib/ urllib2 like :
import urllib2
url = "http://YourUrl/rest/services/sample/MapServer/0/query?where=1%3D1&f=pjson"
data = urllib2.urlopen(url).read()
print data
If you are getting results , then it is not secured.
If you are getting result as '{\n "error": {\n "code": 499,\n "message": "Token Required",\n "details": []\n }\n}' , or any such error , then it is secured.
Case 2:
If the services that you are accessing is not known to you and you can do a simple analysis using the following URL: http://YourURL/rest/services/?f=pjson
and conclude if the services are secure or not secure.