how to create table during plugin installation in side a class

You should run your register_activation_hook after creating object.

class Notification  
    {
        function jal_install()
        {
            global $wpdb;
            global $jal_db_version;
            $table_name = $wpdb->prefix . 'fnotice';
            $charset_collate = $wpdb->get_charset_collate();

            $sql = "CREATE TABLE $table_name (
                    id INT NOT NULL AUTO_INCREMENT,
                    msg varchar(500) NOT NULL,
                    time DATETIME NOT NULL,
                    type varchar(350) NOT NULL,
                    link varchar(350) NOT NULL,
                    status ENUM('0', '1') NOT NULL default '1',
                    PRIMARY KEY (id) )";

            require_once( ABSPATH . 'wp-admin/includes/upgrade.php' );
            dbDelta( $sql );

            add_option( 'jal_db_version', $jal_db_version );

        }


    }

    $obj=new Notification();
    register_activation_hook( __FILE__, array($obj,'jal_install') );