javascript not loading

Firstly, you don’t need to add scripts in footer.php manually.

Secondly, if there are no script dependencies, you have to declare empty array:

array(), rather than array('').

Due this mistake scripts are not loading except Bootstrap.

The correct code is:

function imk_scripts() {
    wp_enqueue_script(
        'bootstrap_js',
        get_template_directory_uri() . '/js/bootstrap.min.js',
        array('jquery'),
        '3.3.5',
        true
    );
    wp_enqueue_script(
        'plugin_js',
        get_template_directory_uri() . '/js/plugins.js',
        array(),
        '1.0',
        true
    );
    wp_enqueue_script(
        'bskit_js',
        get_template_directory_uri() . '/js/bskit-scripts.js',
        array(),
        '1.0',
        true
    ); 
}
add_action( 'wp_enqueue_scripts', 'imk_scripts' );