‘Satya’ is a Sanskrit word- a compound of both ‘truth’ and ‘real’. Reality/truth is what is able to bring things about, to let things be. It is embodied actuality, but not in any relative sense. It might be better to say it is experienced as embodied actuality, but is otherwise inexpressible (potentiality and actuality being dualities in discursive thinking and relatives expressed in language, while absolute reality cannot be bounded in such constructions).
Reality/truth is both ontological and epistemological. Some things are unreal in that they are mistaken perceptions, or false descriptions/information. But whatever is real is reality, and the characteristics of reality are perceptions.
The paradox is that we as perceiving beings are part of reality, so that in a sense through us reality perceives itself, yet at the same time these perceptions are shaped according to the sense faculties and intellectual habits and dispositions particular to our form as human beings.
We can posit that Reality transcends our ordinary consciousness and conventional understanding - even to the point whereat our conventional understanding ends up by recognising its own knowledge as ultimately illusory- but beyond the intellectual capacity and the sense faculties we have our foundation in a reality that is not limited by our conventional understanding, and yet is not separate from it.
Our designations as to whether what appears is rational or irrational are epistemological, not ontological. ‘how to understand or perceive correctly?’ is not a dis-interested question.
Being epistemological, they are conceptual tools predicated on addressing our interests. Having interests- being a being that is interested, conditioned by it's interests (by which I mean, a living being that has needs, and thus is required to negotiate it’s circumstances, to obtain food, shelter, to engage in living and all that that entails including all that humans do) is predicated on being a living being. Reality is real whether we live or die.
The phenomenal world is certainly an experience of change and flux, but what significance is drawn from perceptions of the changes in appearances is relative to the interests and disposition of the perceiver. Sometimes perceptions are false in context of what the perceiver is trying to do with perceptions. While reality ultimately must include both what is conventionally correct and the mistaken perceptions of what is (as mistakes), conventionally we can and should favour what has benefit and appears as supportable by reasoned explanation, for no reason in itself other than it has practical benefit to living. So again, this epistemological paradigm is something connected to life and the interests of the living. Since reality includes both life and death, reality is beyond merely the interests of the living.
Reality thus transcends our designations, including rational and irrational. What is unreal can be exposed because unreal is mistaken perceptions of reality and therefore within our remit to correct.
Rational and irrational find their proper use as verbal and conceptual tools in the context of human relations and to the end of benefiting life. No life, (specifically no human life) no rational or irrational. Even within human life, these concepts have their limitations. Is music rational? Or art, or love. Is death rational or irrational?
Further, just as things such as like ‘human nature’ or the ‘essence of humanity’ etc are likewise designations, or collections of various designations, which may be of benefit, (and usually are since they at least project onto the broadest and most inclusive category which we can all relate to as a commonality- ie, being human) but which ultimately are conceptual and worded projections onto what is not expressible (our being, experience just is as it is- words come after), so too with most abstracts. Their value should be determined (after of course they are investigated for not being based on incorrect perceptions as much as that is possible) on their benefit to living.
Benefiting life, addressing interests, dealing with problems, ameliorating or ending suffering. These are the proper subjects to which the conceptual and verbal designations and tools such as rational and irrational should find their proper use.