~ % grep IPSEC /usr/src/sys/amd64/conf/GENERIC
options IPSEC # IP (v4/v6) security
# The crypto framework is required by IPSEC
device crypto # Required by IPSEC
~ % grep MACSEC /usr/src/sys/amd64/conf/GENERIC
~ %
Even though both will encrypt traffic they have entirely different purposes. IPSec is used for VPNs and can be routed across the internet. MACsec is primarily used to authenticate local equipment and only works on direct ethernet connections.
What are you trying to do? I'm guessing you're actually wanting to create an encrypted tunnel across (inter)networks, in which case MACsec cannot be used.