Q: Texts from My Iphone 6 are not being received by an android user?

Yes it is likely iMessage. Try turning it off, sending him a regular SMS and if ok, then try iMessage again.

Use Messages with your iPhone, iPad, or iPod touch - Apple Support

See if this helps, http://apple.stackexchange.com/questions/198223/how-do-i-send-text-messages-to-n on-iphone-owners-using-the-imessage-app-on-a-mac

You will need to go to Settings> Messages> Send as SMS. This will allow you to send text to Android users.

Hi - I am having the same problem where my iPhone 6 using iOS 9.3.4 and when I send texts to anyone who doesn't have an iPhone, they don't receive my messages, even though I have "Send as SMS" selected in settings. I think this started happening after I updated my iOS. Is this your issue, too?