This is a great question. In the opening chapters of Genesis we have the creation of this world and our first parents. Everything was perfect and wonderful. Adam was given one command. In chapter 3 we see how he broke that one command and the world was plunged into sin and ruin. Given the sin that Adam committed and the tragic consequences for the entire human race, is there any possibility of Adam being in heaven?
The simple answer is that we don't know. There are no Bible verses that tell us clearly where Adam went once he died. We don't know. When it comes to the Bible, or our understanding of God there are many things which we don't know or don't understand. This is a reasonable position to be in. There are things which God has revealed to us that we need to know. There are things which God has not revealed to us that we need to know (Deuteronomy 29:29).
This question though demands a fuller answer.
Looking at this from a hypothetical position - could Adam be in heaven?
The first thing to say is he doesn't deserve to be in Heaven. In fact no one deserves to be in Heaven. We have all sinned and come short of the perfect standard of God (Romans 3:23). There is no one that is good enough to go to Heaven.
The second thing to say is that God as judge is entirely fair and just. When God makes a judgement it will be perfect. He won't make a mistake. "The Judge of all the earth shall do right" (Genesis 18:25). If Adam is in heaven it is not a mistake.
The third point to make is that Adam can be in Heaven. Not because he deserved it but because of the mercy of God. When we think about the Lord Jesus Christ he came to save not "good people" but sinners (Luke 5:32). People who think they are good are really deluded and havent appreciated their sin and what they are like before God. Jesus saves sinners. He saves to the uttermost (Hebrews 7:25). In other words there isn't a person who is too bad to be saved. Even Adam with his sin could be forgiven and cleansed because of the death of Jesus Christ. The blood of Jesus Christ cleanses us from all sin (1 John 1:8-9). Yes Adam can be in Heaven but only because of the saving work of Jesus.
The final thing to say on this question - will you be in Heaven? The only way to be in Heaven is to come to Jesus in repentance and faith. He turns no one away that come to him in faith.
