How to activate WhatsApp on both SIM or dual SIM?

If I understand you correctly, you want to install Whats app with two different numbers on the same device? If so, you can download an app know as "Parallel Space" from Playstore in Android devices. Parallel Space is a clone app which will help you make a replica of Whatsapp, something similar to VMware we use in Operating system to keep two OS.

Also, I don't think so there is any smartphone which will allow you two install Whatsapp with two different number. So better to opt for cloning app and enjoy browsing different social media application like Whatsapp, Facebook, Instagram etc.

I too had such a doubt a few months back when I came to know from a friend that "Parallel Space" App from Playstore would help you for such requirement in Android devices. So, I installed Parallel Space in 64Bit per guideline and opened that app, it will auto tick few apps like WhatsApp, Gmail, FB and others.

You have to check or uncheck the required app and install it to use the required one. Once installed it, you can go to the same Parallel Space app again and would open already selected apps within (like WhatsApp or Gmail etc.) to sign up or sign in for the second account from the very same smartphone.

It is also called 'clone' one. There are other few apps similar to Parallel Space but no idea about those apps. However, this app also would sometime annoy you when ads come. Rest everything is good like you can use two Whatsapp, Gmail, FB etc. in the same Android smartphone or Tablet PC etc.