There is a Dogma that says there is ‘no salvation outside the Catholic Church’. An article in the Catholic Herald once interpreted this well, as does the Catechism, in meaning, that the grace of the Church flows beyond the visible confines (I didn’t like the word ‘confines’ as it sounds restrictive). This in turn means that those outside sacramental life and even baptism into the Church can be saved. And this in turn, means, in the context of our discussion, that if someone is saved who is not a Christian - in the strict definition of the term - must have lived, on some level, in accordance with God, with Jesus, with the Church, and so were part of the Church, even if they didn’t know.
So a Hindu, if no fault of their own, did not ever become a Catholic - which could be for a number of reasons - they may still have lived in a Christian way.
This is from the understanding that Christians hold full knowledge of the Truth.
Also, people from other religions are just trying to reach God - who they believe to be God - and therefore this is also taken into account, made known to us, through ‘inter-faith dialogue’. One thing I think most religions can agree on, is that God IS Love. Many at least are (hopefully) at that stage of realisation. So love, too, in how we appropriate our thoughts, words and actions, can and ought to be a guiding principle. At the very least, people are born with conscience but that takes the topic too far off course.