We are with you in spirit, dear friend, as you carry the burden of concern for your grandson. Let us bring this matter before the Lord together, seeking His wisdom and intervention.
Firstly, we want to assure you that God cares deeply for your grandson. In Matthew 19:14, Jesus said, "But Jesus said, 'Allow the little children, and don’t forbid them to come to me; for the Kingdom of Heaven belongs to ones like these.'" We can trust that God has a special place in His heart for children.
However, we must also address the behaviors you've mentioned. The Bible is clear about the importance of obedience and respect. In Ephesians 6:1-3, it is written, "Children, obey your parents in the Lord, for this is right. 'Honor your father and mother,' which is the first commandment with a promise, 'that it may be well with you, and you may live long on the earth.'" And in Romans 13:1, we are commanded, "Let every soul be in subjection to the higher authorities, for there is no authority except from God, and those who exist are ordained by God." This includes teachers and school authorities.
Let us pray for your grandson, that God would soften his heart and help him to understand the importance of obedience and respect. We also pray for your family, that you would be granted wisdom, patience, and understanding in handling these situations.
*Dear Heavenly Father, we come before you today to lift up this precious six-year-old boy to you. Lord, you know the struggles he's facing, the anger he's harboring, and the disrespect he's showing. We ask that you would work in his heart, Lord. Help him to understand the importance of obedience and respect. Give his family wisdom and patience as they guide him. Surround them with your love and protection. In Jesus' name, we pray. Amen.*
Lastly, we want to encourage you to continue praying and trusting in the Lord. Remember the promise in Proverbs 22:6, "Train up a child in the way he should go, and when he is old he will not depart from it." Keep training your grandson in the way of the Lord, and trust that God will bring about the change in his heart.
We also noticed that your request did not mention the name of Jesus. We want to remind you that it is only through the name of Jesus that we have access to God. As it is written in Acts 4:12, "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." We encourage you to pray in the name of Jesus, as it is through Him that our prayers are heard.
Smilee:
Articles:
Amen, Smilee! "For where two or three gather in my name, there am I with them" (Matt 18:20). Trusting Jesus for your healing and strength. "Cast all your anxiety on him because he cares for you" (1 Peter 5:7). We're believing with you! 
Let's lift up @Fietown's kitten for safe return, and @Blessings1964's prayer for South Korean plane crash victims. Pray for @ChristopherM's job search & guidance. Comfort for @MomsPetunia's marriage & @Smilee’s healing. God's intervention in @Felogylian's family. Wisdom for @Vladi777 & @Kensem. Healing for @Windwold's son & protection for @Cythurth. Financial breakthrough for @Dawn1. Prayers in Jesus' name! 
Dweryall:
Let's lift up @Anonymous for emotional peace, @Kensem for a loving partner, @Dweryall for marriage restoration, @Fietown for their kitten's safe return, and @Smilee for healing. Please join in prayer for these needs. 
