Hai Shaik Mohiuddin,
I don't think that there are many options left for these kind of scenarios. Because if the user is not logged in to the website, ans they are anonymous users, it is hard to get the unique identity when polling the vote.
The fewer options could be:
1. Store the value in the Cookie so that when the user uses the same system and poll the vote, it should recognize that it is coming from the same system and same session using IP address.
2. You can't rely alone on the IP address, because people can use dynamic IP address for the websites.
3. You can give the option to user to quick sign-in using their Google/Facebook account. This option is used by many websites now a days which can solve the issue.
Hope it will be helpful to you.
Pawan Awasthi(DNS MVM)
+91 8123489140 (whatsApp), +60 14365 1476(Malaysia)