So, we reached to Nokia with our query about WhatsApp and while they refuse to give a fixed date, they hope WhatsApp for Nokia X coming very soon. So, keep fingers crossed!!
In the meantime there are three workarounds,
Install WhatsApp on your Nokia X and even if it says “your device is not supported” try opening it from Fastlane and you may be able to do so. If Fastlane opening doesn’t work ask any of your friends send a message to you on WhatsApp, and if you let this chat thread remain in Fastlane, you can access your WhatsApp.
In case you are not impressed with above workaround, try WhatsApp+, which brings you all WhatsApp features and some more and is free. Download it from here.
We have found a third workaround as well. Here is one more way in which you can use any version of WhatsApp on Nokia X, Nokia X+ and Nokia XL