I want to connect GCP infrastructure with OCI infrastructure so that all the services can communicate on the private network instead of allowing public IP which the traffic get comes.
as per my findings, I found Equinix can provide what I'm looking for but again that's a totally different thing, and introducing it in the current environment is impossible.
isn't there any service that GCP or OCI provide for the same ?
I would look into using a NaaS provider like PacketFabric, Megaport, or even I think Equinix has a solution to connect Multi Clouds.
You would essentially use Google Interconnect and Oracle FastConnect with a NaaS in the middle providing the link.
It depends on what you are looking for but if you are looking for a private, secure, and low latency connection between Google and OCI, go with a NaaS, otherwise, a VPN over the internet should work too.