How can I merge two compositions from different projects?

it's a very basic thing in AE, inport the 6 sec project inside the one minute project and create a new comp 1 min and 6 sec thane drag both comps inside your new comp 

I disagree with all you're methodes. The easiest is:

1. If the compositions are finished save them

2. After wich you change the composition settings here you need to change the end timing tot your end time do this for both compositions.

3. Save them both again.

4. Create a new project.

5. Select import drop down menu and select the file option

6. Now import both *.aep files, they will show up as folders

7. Create a new composition and import the old compositions from the folders in After Affects (can be achieved by drag and dropping)

Here is how I would do it:

1. Save the project with the six-second comp as "Merged Project"
2. Import the project with the one-minute comp into "Merged Comp." It will show up in a folder.
3. Reveal the contents of said folder and find the one-minute comp
4. Drag this entire one-minute comp into the timeline of your six-second comp. If needed, set the duration of this comp to be 1min and 6 sec. Select the minute long comp in the time line, go to the 6-second point and hit "["

That's it.

There are many ways here are a few. I suggest going with the first method.

• Select all items on the timeline in the minute long composition , copy , then go to your your 6 second comp, position your insertion bar to the end  and paste the keyframes, you may need to extend the length of your composition in your settings
• render out each composition to a format such as .mp4, and then import each into a new composition
• precompose each of your compositions, and  copy and paste them into a new composition. Either method will work, you can think of precomposing as grouping if you are new to after effects

depperiousity,

You should ask over here (or should I say over there?):

After Effects