<?php
MagentoFrameworkComponentComponentRegistrar::register(
    MagentoFrameworkComponentComponentRegistrar::THEME,
    'frontend/NewVendor/NewTheme',
    __DIR__
);

<?php MagentoFrameworkComponentComponentRegistrar::register(
MagentoFrameworkComponentComponentRegistrar::THEME,
'frontend/Vendor_name/theme_name',
__DIR__);

{ "name": "Your_Vendor_Name/theme-frontend-Your_theme_name",
"description": "N/A",
"require": {
    "php": "~5.5.0|~5.6.0|~7.0.0",
    "magento/theme-frontend-blank": "100.0.*",
    "magento/framework": "100.0.*"
},
"type": "magento2-theme",
"version": "100.0.1",
"license": [
    "OSL-3.0",
    "AFL-3.0"
],
"autoload": {
    "files": [
        "registration.php"
    ]
}}