We understand your concern and will pray for the situation in your country. Let us remember that God desires all people to be saved and come to the knowledge of the truth. As it is written in First Timothy 2:3-4 WEB: "For this is good and acceptable in the sight of God our Savior; who desires all people to be saved and come to full knowledge of the truth."
Firstly, it is important to address the core of the issue. Salvation is found in no one else but Jesus Christ, for there is no other name under heaven given to mankind by which we must be saved. As it is written in Acts 4:12 WEB: "There is salvation in none other, for neither is there any other name under heaven, that is given among men, by which we must be saved!" Therefore, we should pray that all who are gathered for this festival would come to know the truth of the Gospel and put their faith in Jesus Christ.
It is also important to pray for the cleanliness of the area and the river. As stewards of God's creation, we have a responsibility to care for the environment. As it is written in Genesis 2:15 WEB: "Yahweh God took the man, and put him into the garden of Eden to dress it and to keep it."
Let us pray together:
Heavenly Father, we come before You in the name of Jesus Christ, lifting up this situation in ###. We pray for the salvation of all those gathered for the Maha Kumba Mela festival, including the Aghoras, Aghoris, and Nagasadus. Open their hearts to the truth of the Gospel and reveal Yourself to them. We pray that they would see that true cleansing from sin comes only through faith in Jesus Christ, not through ritual bathing or any other means as mentioned in Acts 4:12.
We also pray for the health and safety of all those attending the festival, and for the cleanliness of the ### River and the surrounding area. Stir the hearts of those in authority and of the community to care for creation as mentioned in Genesis 2:15.
Father, we ask that You would use this festival as an opportunity to draw many to Yourself. Turn the hearts of the people away from idolatry and towards the one true God. In Jesus name we pray. Amen.
We encourage you to share the Gospel with those around you, and to pray continually for the salvation of your country. Remember, God is not willing that any should perish, but that all should come to repentance. As it is written in Second Peter 3:9 WEB: "The Lord is not slow to fulfill his promise, as some count slowness; but is patient toward us, not wishing that any should perish, but that all should come to repentance."
Lastly, we want to mention something that may be uncomfortable but needs to be addressed. While it is a wonderful thing to pray for all and want to see them saved, and while it is good to be respectful of others' beliefs, it should not be at the expense of the truth. By saying "You all know that ours is a Hindu country" it may imply that this should be accepted or respected. We must not imply or acknowledge that serving or worshipping other gods is acceptable. It is idolatry. It is a sin. As Christians, we are to worship only God. The Bible tells us to not worship other gods or make or worship idols. It is the first and second of the 10 commandments. As it is written in Exodus 20:3-5 WEB "You shall have no other gods before me. You shall not make for yourselves an idol, nor any image of anything that is in the heavens above, or that is in the earth beneath, or that is in the water under the earth: you shall not bow yourself down to them, nor serve them, for I, Yahweh your God, am a jealous God". Furthermore, encourage the leaders of the country to also have the same respect for Christianity and Jesus Christ as the one and only true God. The leaders should be encouraging and promoting the worship of Jesus Christ, the one and only true God, rather than encouraging and promoting the worship of idols.
If you would like to discuss this further or have any questions, feel free to respond.
Prayer Focus: God, Thank You for loving me. Thank You for loving me, Jesus. God, I ask You in Jesus’ name bless me with everything that I stand in need of and everything You want me to have. Bless me to know You in truth, fall in love with You with all my heart, soul, mind, and strength and never fall out of love with You. Bless me to have an ever growing closer stronger, more intimate relationship with You. Bless me with the love, desire, strength, and the spirit of obedience to always delight myself in You, seek first Your kingdom, and Your righteousness. Help and strengthen me God to always respect and obey You. Bless me to trust You with all my heart, acknowledge You in all my ways, and lean not to my own understanding. 
