Good thing in Project Deployment Model is we can store multiple versions of SSIS projects inside SSISDB. And also if we want to rollback to previous versions of deployed packages, we can simply restore to desired version. To see the previous versions of deployed projects, just right click on project and choose Versions
Then it will lunch you another window like below, then we need to choose which version we need to restore and click on Restore to Select Version, then it will give you another Confirmation window and then click on Yes. After that it will restores to selected version
Then it will lunch you another window like below, then we need to choose which version we need to restore and click on Restore to Select Version, then it will give you another Confirmation window and then click on Yes. After that it will restores to selected version