The Bible teaches quite clearly that “Jesus is the only parameter to go to heaven.” This is not exactly what Peter said in Acts 4:12, but it is close. “Salvation is found in no one else; for there is no other name under heaven given to mankind by which we must be saved.”
Your friend says that she does not like this, therefore she will not believe in Jesus. This is an interesting position to take. The idea is that if I do not like something I will not believe in it. Let us say that we do not like gravity. Therefore we do not believe in it. This philosophy will be hard to maintain if one steps off of a cliff. Someone says, “I do not like eating, therefore I will not eat.” Again, not a good idea. Let us suppose that what Peter said in Acts 4:12 were true. If so, then refusing to be a Christian because one does not like this is a possible option, but the results of not accepting Jesus because you do not like him would be an utter disaster. I understand the emotion your friend is feeling, but let us ask a common sense question: Should we let the fact that we do not like a particular fact about the world cause us to not believe that fact?
Since when did God have to do what we like? Who says that we get to determine what God should be like? If I do not like believing “in a religion that doesn’t give everyone a chance,” what if it were reality nevertheless? What if it were true? Then would rejecting this idea be a good idea? Is one willing to go to hell for eternity as a protest against a God that we do not agree with? Like God says in Romans 9:20, “Who are you, oh man, to talk back to God?” It is not a wise thing to thumb our nose at the actual God who exists because we do not agree with all aspects of his nature. In the end, we will give account to God. I believe that God is good–completely good, but even if there were some aspect of him that we do not like, surely we should honor the actual God who created us and gave us life!
From an emotional perspective, I can see why your friend is bothered by the fact that, until fairly recently, most people in India had a very limited exposure to Christianity, yet they will be judged in the end by things taught by Christians. On the face of it, this can appear unfair, and I get it. Yet, despite my quote above from Acts 4:12, and despite the fact that I believe Jesus is the only way to be saved, I still believe that God is just and fair. In fact, this is one of his attributes. I am convinced that we will be held to judgment based, not on what would do not know or what we have no access to, but to what we know and what we have access to. Romans 2:14-16, as you mention in your questions, points in that direction. Now, I am not God, and I am not in a position to say how many born in India in the year 535 BC will be “saved” in the end and will be in the new earth with God. I am not given access to that information. However, if we are not saved by Jesus, then we are judged according to our conscience, if I read Romans 2:12-14 correctly. In that case, I would MUCH rather be saved by obeying Christ than by coming before God based on whether I obeyed my moral conscience. In fact, even now as a believer, I do not always obey my conscience. Before I was a Christian, I violated my conscience an uncountable number of times. I definitely do not want to come before God on judgment day based on Romans 2:12-14. Yet, I believe that there may very well be some very “good” Hindus and Buddhists who might possibly be with God for eternity. However, even if they make it based on Romans 2:12-14, even then, it will only be through Jesus, who is the only name by which we can be saved, even if we do not know of him. Jesus, after all, is a lamb of God, killed, from God’s perspective, “from the foundation of the world.” (Revelation 13:8) From God’s perspective, Jesus has always been slain, so that Jews before Jesus can be with God in eternity, as may some non-Jews as well.
Here is the bottom line. Even if it is at least conceivably possible that one might make it to “heaven” through personal righteousness rather than through being a Christian, surely that likelihood is extremely small, whereas, if one becomes a Christian, then one is guaranteed salvation if one remains faithful (Ephesians 1:13-14). Wouldn’t it be far better to put our faith in Jesus than to hope for the best? Wouldn’t it be better to worship God the way he wants to be worshiped? What is the advantage of NOT being a Christian? None. Zero. Nada. My suggestion is that you not be swayed in your faith by the emotions you are feeling over this question.
Besides, the premise of your friend’s complaint is somewhat weak. Everyone in India knows about Jesus. Every single one. The days when people did not have access to Christianity, to Bibles and even to Christian churches have long passed for more than 95%, maybe even 98% of all people today. There is virtually no one left in the world today (which is all that really matters for us right now, after all) who does not have the opportunity to be saved by Jesus.
Your friend is hurt that those who do not believe in Jesus will not be saved. I understand and respect that emotion, but if it is true, then being hurt by the facts is worth mentioning, but it should not guide our actions. I understand the emotion, but nevertheless suggest that your friend do what is right, which is to believe in the actual, real God, which is the God of the Bible, and be saved by the blood of Jesus. Being swayed from truth by our emotions is not a good idea. The fact is that Jesus walked on water, healed the sick, raised Lazarus from the dead and calmed great storms. He fulfilled all the prophecies of the Messiah. He gave sufficient evidence that he is the Son of God.
If your faith has been diminishing this year, then I suggest you consider what God has done for you and decide today to let your faith be rekindled. God has loved you very much. God sent his one and only Son to die for you. Do not let yourself be sucked into the world. There is nothing good for you out there.