I think I see what you’re driving at, if I’m wrong let me know.
First, the Catholic Church does not ‘damn’ anybody. (Bet that’s a relief!)
Now, the Catholic Church is the one true church. But there are, outside the Catholic Church, for various reasons, other churches, other faiths.
The Catholic Church does teach (I think I can find the relevant paragraph in the CCC) that other faiths can contain “some” truth.
Further, it considers that all peoples–no matter what faith, or no faith–that they profess, are members of the Catholic church.
It further teaches, in paragraphs 839 and on, that
Those who have not yet received the Gospel are related to the People of God in various ways."325
From 843:
The Catholic Church recognizes in other religions that search, among shadows and images, for the God who is unknown yet near since he gives life and breath and all things and wants all men to be saved. Thus, the Church considers all goodness and truth found in these religions as "a preparation for the Gospel and given by him who enlightens all men that they may at length have life."332
844 In their religious behavior, however, men also display the limits and errors that disfigure the image of God in them:
Very often, deceived by the Evil One, men have become vain in their reasonings, and have exchanged the truth of God for a lie, and served the creature rather than the Creator. Or else, living and dying in this world without God, they are exposed to ultimate despair.333
845
To reunite all his children, scattered and led astray by sin, the Father willed to call the whole of humanity together into his Son’s Church. The Church is the place where humanity must rediscover its unity and salvation. The Church is “the world reconciled.” She is that bark which “in the full sail of the Lord’s cross, by the breath of the Holy Spirit, navigates safely in this world.” According to another image dear to the Church Fathers, she is prefigured by Noah’s ark, which alone saves from the flood.334
So you see, it is not a question of ‘denying somebody their truth’.
Truth is truth. It is not ‘your truth’ or ‘my truth’. The truth that is found in your Hindu’s religion is the same truth found in the Catholic religion IF it is truth. If a Hindu holds as a truth that Vishnu is a real god, that is not a truth, however much he wishes it. But the ‘ultimate truth’–the idea that there is ‘a God’, is believed by that Hindu (even if he calls god, ‘vishnu’). And THAT truth–the truth of a supreme God–is true.
We cannot have an ‘equality of truth’ such that we say, "well, I believe in Jesus but you who believe in anything and nothing are entitled to what you hold as true for you’. But we do not necessarily say, “All that you believe and hold as true is a LIE”–because as seen above, that is not so. There is a kernal of truth in all religions (even Satanism, because Satanism’s truth is seen in its reversal–worship of Satan is a twisting of worship of God, just as evil is a spoiling or reversal of good. It is not ‘good’ to worship Satan, but the instinct to worship is not evil–the OBJECT of that worship (Satan) is.)