Basically, we can either claim that God can be known through reason alone (Samuel Clarke, Anthony Collins, Voltaire, Kant, Nyāya, Śaivasiddhānta…) or that S/He can be known through personal insight and/or Sacred Texts (Śrī Vaiṣṇavas after Yāmuna, Gauḍīya Vaiṣṇavas…).
Is Indian Philosophy “caste-ish”? Yes and no, in the sense that each philosophy is also the result of its sociological milieu, but it is not only that.
Is Indian Philosophy only focused on “the Self”? Surely not.