Can we make Cluster of 2 individual RAC

Hello All,

I have one query that. I have 2 separate systems both are the Oracle 12c RAC 2 Nodes .

Now if any of the system's Common Storage (attached with SAS to the 2 Nodes) is failed so no this system will not work. This situation is single Point failure.

So we required to resolve this kind of situation..

so what are the possibilities to resolve this situation.

One possibility i am exploring that i have

4 Server grade Nodes and 2 Common Storage (With dual controller)

We make 2 individual 2 Node RAC and then make Cluster of that?? Is it possible??

Or can we have other options???