The city of Northern India referred to in the crossword solution is DELHI, which is the capital of India and one of the largest cities in the world. It is located on the banks of the Yamuna River in the northern part of the country and is home to more than 25 million people. DELHI has a long and rich history, having served as the capital of several empires throughout its existence. It is also known for its vibrant culture, with many festivals and events taking place throughout the year.