To determine if you can upgrade directly from version 16.3 to 16.12 on your Cisco device, you should consult the release notes for version 16.12. These notes should provide information on any required intermediate upgrades, as well as any other considerations you should be aware of before upgrading.
In general, it is best practice to review the release notes for any software upgrade to ensure a smooth and successful upgrade process. The release notes will typically include information on known issues, new features, and any upgrade prerequisites.
1) Log in to your Cisco account on the Cisco website.
2) Navigate to the "Software" section of the website.
3) Select the product family and model of your Cisco device.
4) Locate the IOS software version you want to download
5) Before download clic on release notes
According to the switch model mentioned C3850 is compatible with the version you need upgrade
**Remember to support with a like to keep the community active***
**Please, if the information was helpful, mark this answer as correct.***
