Follow this page: http://www.vladan.fr/realtek-8169-nics-not-detected-under-esxi-5-5/
Add the vibs to a datastore, then run the following commands:
esxcli software vib install -v /vmfs/volumes/drobo01/VMware_bootbank_net-r8169_6.011.00-2vmw.510.0.0.799733.vib
To see all the vibs installed:
esxcli software vib list
thanks for sharing.