If one were to see self, it would be initially quite an insight, because that self is always in the background of experience. (for a putthujana, and ariya, except arahant).
In regard to everything and every experience, there is a self in the background. (for a putthujana, and ariya, except arahant)
The self can be defined as a vague ambiguous thing, ‘floating’ in the background. It cannot be defined as any of the aggregates, for it is in regards to them.
Therefore, one who actually, understood self, as an ambiguous phenomenon, would potentially become stuck there, in that knowledge, or composed in that (wrong)mindfulness of self as the overarching phenomenon governing all things. A thing that has always been there, unchanging since one can remember.
So there is a self, Ramana Maharshi is right in that sense.
However, he seemed not to realise that the self, that vague phenomenon is an assumption, determined by ignorance i.e it cannot be owned, it is determined by that which it is not.
If there were no aggregates or even if there was no experience of things, then that self could not be discerned either.
The self is only known because of the rest of the world is in relation to it i.e it is determined by this very NON-knowledge of the principle of paticcasamupada.
He was apparently authentic enough to recognise a vague ambiguous self- atta, but seemed not to go further as in attaining right view by seeing that, that atta was an-atta.
However, it seems that he was most likely free of sensuality, which is possible. If he came across the Buddha’s teaching and dwelt on it, he most likely would have understood it relatively quick.