The interior layout is completely flexible. From "all dividers out" to a wide variety of divisions. If I go all out there are 2 XT2, maybe 1 X100f, a total of 4 fixed focal lengths, 1 flash with transmitter and several camera batteries in it. So it should be enough for your equipment 

Hello, according to research you need an Olympus OM Lens Mount to Micro Four Thirds Mount Adapter for this combination. 

Hello, I have an olympus om-d e-m10 mark iii and an olympus analogue lens. do the two fit the adapter? Answer: Hello, according to research, you need an Olympus OM Lens Mount to Micro Four Thirds Mount Adapter for this combination. Best regards, Urth support From Urth EU SELLER on September 7, 2021 If you want to convert an old Olympus OM lens to a current Micro 4/3 mount, you can search under "OM to Micro 4/3 Adapter". K&F Concept also offers something like this. My adapter was for Sony e. However, these adapters usually do not transmit any data (e.g. aperture value, distance, automatic functions ... unless the lens was intended for this. But then the adapter costs a lot of money). 

no it will not the eos-r has a different mount 

For camera with telephoto zoom lens, you need to buy a tripod mount ring additionally or telephoto lens bracket for better balance)