Does vscode editor support .inc file highlight?

2018 Update - Visual Studio Code 1.24.1

Its;

File > Preferences >  Settings

You will get a dual pane as below ;

Default User Settings     || User Settings
"files.associations": {}

Copy that over to the User Settings Pane ( right pane ) and paste at the bottom ( before the closing parentheses );

 ... || User Settings
          "files.associations": {
           "*.inc": "php"
          }
        } // closing parentheses

.inc files are used in multiple languages; what language are you using them in?

You can tell VSCode to apply language-specific syntax highlighting by editing the settings.json (File > Preferences > Settings) by adding the file extension to the highlighting category.

For example, to highlight .inc files as PHP,

{
"files.associations": { "*.inc": "php"}
}  

See this link for more details.