i would like to hide some i individual whats app conversations in android mobile. kindly anyone suggest me some free android app for the said purpose ?
I don't think you can, unfortunately... You can only hide Whatsapp entirely by using Knox if you have a newer Samsung device or a 3rd party app with password-protected workspace functionality. That way you can hide your app and app activity under a protected space that's only accessible if you provide the right credentials. But if you still want Whatsapp to be available to the 'normal' workspace, all of your conversations will be there unless you delete them.