The version of Java 6 linked to by Old Toad (twice!) is the correct one. I've installed it in Sierra with no issue and tested Illustrator CS6 with it, which also requires the old Java version.
Java 8, linked to by OnTheEdge1 will not help at all unless you fudge the system after installing that to make it believe Java 6 has been installed.
BUT!!! I also tested applying the trick to fool the OS into believing Java 6 had been installed, and apps I have that "require" Apple's legacy Java ran with no version of Java installed at all. Not 6 or 8.
If you want to give it a try, do the following:
First disable System Integrity Protection, or you won't be able to do steps mentioned next. To do that, restart and hold the Command+R keys to boot into Recovery Mode. Once there, launch Terminal from the menu bar and enter:
csrutil disable
Then enter reboot to restart the computer.
Back at the normal desktop, enter the two lines below in Terminal, pressing enter after each one. You will be asked to enter your admin password the first time.
sudo mkdir -p /System/Library/Java/JavaVirtualMachines/1.6.0.jdk
sudo mkdir -p /System/Library/Java/Support/Deploy.bundle
Once again restart into Recovery Mode to re-enable SIP. Only this time in Terminal, enter:
csrutil enable
Followed again by reboot.
These commands create the two files noted at the end of each path name. They are nothing. Just zero byte names. But apps that look to verify Java 6 has been installed now think it has.