To see if my friend is online in imessage

DeRf KuN wrote:

is it possible to see or know if my friends that is using imessage if she is online or offline?

No, because that's none of your business. Now, if your friend wants you to know, perhaps she will use the Find My Friends app and allow you access.

If you want this feature, let Apple know about it by using this link:

Apple - iPhone - Feedback

This is not a current supported iMessage capability. Sorry.