Aim of christian missionary in India

The aim of Christian missionaries is to present the good news about Jesus Christ, for:

there is salvation in no one else, for there is no other name under heaven given among men by which we must be saved. - Acts 4:12 ESV

As well as preaching this good news, they are mandated with the task of making disciples of those who respond to this message with repentance and faith, teaching them to obey the commandments of Christ, which can be summarised as:

And he said to him, “You shall love the Lord your God with all your heart and with all your soul and with all your mind. This is the great and first commandment. And a second is like it: You shall love your neighbor as yourself. - Matthew 22:37-39 ESV

Their role is not to interfere with the politics, economics or industries of nation-states but:

If possible, so far as it depends on you, live peaceably with all. - Romans 12:18 ESV

You refer to the Dalits as a "backward caste", such a view warrants further examination, as it is far more likely that what causes "fault-lines" resulting in "harm to national integrity leading to national disintegration" are not the actions of Christian missionaries, but a pernicious persistence of the caste system itself.

Christians believe that:

1. There is one God, who created everything in the universe, and He is perfect -- He has never done anything bad. He is also eternal -- that means He was alive before anything was created, and will be alive forever.
2. All people (including Christians) break God's rules, and so all of us are evil.
3. There's no way for people to be good enough to please God by themselves.
4. Because we're all bad, and God is good, we all deserve to be punished. So when we die, we are going to be judged, and we will punished for eternity for breaking God's rules.
5. But people are God's creation, and He loves every single one of us on Earth, so He does not want anyone to be punished when they die. God is a perfect Father, who loves His children, and wants them. So, He made a way out of the punishment for us: He sent His only Son, Jesus Christ, to be born as a human being, and live among us. Jesus was the only person in history to ever live a perfect life, without doing anything wrong. God sent Him to be punished instead of us, so that everyone who trusts in Jesus, and wants to stop doing bad things, can be saved from God's punishment. This means you will get to be with God, forever in heaven when you die.
6. God will help that person who trusts in Jesus to stop being evil, by filling him or her with His Holy Spirit.

Christian missionaries in India don't want to change your government. They want your heart to be changed by believing in Jesus Christ, and trusting only in Him as your Savior, so that you don't have to suffer punishment when you die, and you can be a friend of God because of His gift.

In fact, Christians believe we need to obey the human government and do what it says, whether we are in India or anywhere else-- unless it is different than what God says for us to do.

Christians are supposed to be peaceful and they want to bring you Jesus's love. If you are seeing missionaries that are not acting like that, then they are going against what God tells us in our Bible, and you should stay away from them. Otherwise, please consider their message.

There is no conspiracy. In the West, we help fund Christian missionaries in India and other parts of the world because we truly believe that Jesus is the Son of God, and you need to believe in Him to get to heaven. We love God, and we love you, and we want all people in the world to go to heaven.

Source: The Bible - https://www.bible.com/hi/bible/819/jhn.1.hhbd

Christians go to missions inspired and commanded by the book of Matthew. Precisely:

And Jesus came and spake unto them, saying, All power is given unto me in heaven and in earth. Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen.

(Matthew 28:18-20, KJV)

A true missionary is formed by 3 components: Himself, the one who is sent to missions. A prayer team that prays for him and a supporter team, that supports the missionary financially.

Real missionaries go to other countries to preach and share the gospel with people that never had the chance to hear about it or where the gospel is something forbidden. They aren't influenced by large western corporations or rich people in order to cause damage in the countries they go to.

I can't really tell you whether there are like fake missionaries with these intentions, but for sure those aren't the plans neither the objective of the christian world. Jesus commanded christians to go to other countries to share what he taught in earth and that is what true christians do.