Make sure you are at least CU5 for BizTalk 2016 as that added the support for TSL 1.2, also read the Support for TLS 1.2 protocol in BizTalk Server. For earlier versions of BizTalk you also needed to install SQL Server 2012 Native Client version 11, however I believe that should already be there for BizTalk 2016, but worth checking
Failed to load Group BizTalkMgmtDb in BizTalk 2016 FP3 after disabling TLS 1.0
Failed to load Group BizTalkMgmtDb in BizTalk 2016 after disabling TLS 1.0.
Registry Entry have been done
New-ItemProperty -Path '.\SOFTWARE\Microsoft.NETFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -PropertyType DWORD -Force | Out-Null
New-ItemProperty -Path '.\SOFTWARE\Wow6432Node\Microsoft.NETFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -PropertyType DWORD -Force | Out-Null
New-ItemProperty -Path '.\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Client' -Name 'DisabledByDefault' -Value '0' -PropertyType DWORD -Force | Out-Null
New-ItemProperty -Path '.\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Client' -Name 'Enabled' -Value '1' -PropertyType DWORD -Force | Out-Null
New-ItemProperty -Path '.\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Server' -Name 'DisabledByDefault' -Value '0' -PropertyType DWORD -Force | Out-Null
New-ItemProperty -Path '.\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Server' -Name 'Enabled' -Value '1' -PropertyType DWORD -Force | Out-Null