Deploying Custom Solutions in SP 2016 to Subscription Edition

Hi Ketan Gandhi, it's difficult to answer that question without knowing the specific details of your solutions. But in general, solutions that are compatible with SharePoint Server 2016 should be compatible SharePoint Server Subscription Edition as well.  However, keep in mind that SharePoint Server Subscription Edition introduces modern UI and new site templates like the Modern Team Site and Communication Site.  So solutions that depend on classic UI may not be compatible with modern UI.  (Note that the modern UI in SharePoint gives you the option to switch to the classic UI to access any functionality or capabilities that aren't available in the modern UI.)

FWIW, SharePoint 2010 was based on .NET Framework 3.5 while SharePoint 2013 was based on .NET Framework 4.5, so that's a significant reason why .NET-based solutions may need to be recompiled.  Future versions of SharePoint Server have continued to use .NET Framework 4.x, with SharePoint Server Subscription Edition using .NET Framework 4.8.