Which tcp/ip model layer would a mac address be found?

in layer1 (network access layer) and layer2 in OSI

network access

Physical address (MAC as in Ethernet) is found in Data-link Layer.

Please note that physical layer is just responsible on how to represent0s and1s, Link speed and duplex.

The second layer

layer1  of  TCP / IP Model that is Network Access Layer

Layer1 (Network Access ) Layer. 

Mac Address information is on L2 layer2 that is Datalink Layer .

the Datalink layer has sub layer called Medeo access control which this sublayer has the information of MAC address.

in Layer1 network access layer

network access

Data Link Layer

You can find the MAC address in Network Access layer of TCP/IP Model.

Where as in OSI Layer you can find the MAC address in Data Link Layer.